Implantation vs period cramps: Differences & what they feel like

Implantation is a process when a fertilized egg attaches to the uterine lining. This process might cause light early pregnancy cramps or other symptoms such as bleeding. While many pregnant people may report feeling implantation cramps, unfortunately, there isn’t much conclusive research out there on the topic of implantation cramps and other symptoms. 

While you may be eager to find out whether or not you may be pregnant, it’s too early to tell for sure at the point of implantation. That said, having knowledge about your body is helpful at all points in our fertility journey, so let’s take a closer look at this early pregnancy symptom. 

What does implantation feel like?

The way implantation feels varies from person to person – all of our bodies are different, and that influences how we experience things. For some people, implantation might feel like nothing. Others report feeling distinct cramping sensations that resemble mild menstrual cramps, though this hasn't been extensively studied scientifically. Most discussions around the topic are anecdotal, rather than evidence-based. No published medical studies clearly confirm or deny that cramping during implantation is a reliable sign of pregnancy. However, the medical community acknowledges that light bleeding can occur around the time of implantation, but notes it can have several causes during early pregnancy [1].

Where do you feel implantation cramps?

Some report that they experience implantation cramps in their lower abdominal or lower back region, similar to where period cramps can be felt.

Implantation cramps vs period cramps

Early pregnancy cramps and period cramps happen due to two slightly different processes in our bodies. Period cramps happen when substances called prostaglandins cause the muscles and blood vessels in the uterus to contract at the end of our cycles when the implantation of the fertilized egg hasn’t happened [2]. Implantation cramps are believed to occur when the fertilized egg attaches itself to the uterine lining—one of the earliest stages of pregnancy [1].

However, implantation cramps can feel very similar to period cramps, and it’s easy to mistake one for the other—which makes them difficult to measure or study reliably, since the symptoms are non-specific and often overlap with normal premenstrual discomfort. So, how can we tell what we are experiencing? Well, there are some tell-tale signs we can look out for:

• Intensity of pain: Most often, implantation cramps are reported to be milder compared to period cramps.
• Cramping sensations: Some people report that implantation cramps feel more prickly, tingling, or like pulling and might come and go in waves. Period cramps might feel like dull, aching pain.

When does implantation occur?

Implantation occurs only if a fertilized egg successfully attaches to the uterine lining, typically about six to ten days after ovulation [3]. While fertilization is necessary for implantation, not all fertilized eggs implant. Once implantation happens, the body begins to support the embryo’s growth by supplying oxygen and nutrients [4]. 

Implantation signs and symptoms

So, how can we recognize implantation cramps? Well, implantation cramps could feel similar to period cramps, and it might be hard to differentiate between them. 

Early pregnancy cramps might or might not be accompanied by other symptoms like implantation bleeding, which is a type of light bleeding or spotting. There is not enough scientific evidence to support that implantation bleeding is a common phenomenon, and bleeding during early pregnancy can happen for a number of reasons. In fact, it’s thought that as many as 25% of pregnant women might experience bleeding in the first trimester — some of this bleeding could theoretically be caused by implantation, but more research is needed [1]. 

The most reliable way to know whether your symptoms were due to implantation is to wait until you’re able to take a pregnancy test. We know that the so-called two-week wait between ovulation and the expected period can be challenging when you’re trying to conceive, especially if you’ve been trying for a while. However, avoiding stressing over small symptoms like cramping or light bleeding is best for your physical and mental health during this period, so try to remain patient.

What else can cause cramping?

Aside from implantation or period, there are various reasons why you may experience cramping. One of the most common reasons is PMS, known as premenstrual syndrome, which many people experience as their periods approach. As the uterus prepares to shed its old lining, it contracts, causing mild to severe cramps [5]. Other cramping reasons could be:

• Polycystic Ovary Syndrome (PCOS): It’s one of the most common reproductive conditions affecting many people, which increases the chances of experiencing cramping [6].
• Uterine fibroids: These non-cancerous growths that develop from the muscle tissue of the uterus have a variety of symptoms such as heavier, longer periods and cramping (among other things) [7].
• Pelvic Inflammatory Disease: It’s an infection of female reproductive organs that is often caused by untreated sexually transmitted infections, such as gonorrhea and chlamydia, and one of the symptoms can be mild lower stomach cramping [8].
• Endometriosis: A condition where tissue similar to the lining of the uterus grows outside it, affecting 1 in 10 women of reproductive age. One of the most common symptoms can be cramping [9].
• Inflammatory bowel disease (IBD): Not a reproductive system condition, but an inflammation of the digestive system that affects many people, and one of the symptoms can be stomach cramps [10].
• Ovarian cancer: In very rare cases, cramping could be a sign of ovarian cancer. [11]

Most of these causes are often accompanied by additional symptoms such as fatigue, bloating, pain during sex, etc., and the cramps may be much more severe than regular period or implantation cramps.

How long do implantation cramps last?

Reportedly, implantation cramps usually don't last too long. The cramping can come and go in waves and usually resolves within a couple of days [12].

How to ease early pregnancy cramps

For most people, early pregnancy cramps are mild and don't significantly disrupt their daily lives. However, if you experience implantation cramps and they're causing you discomfort, there are certain things you can try to ease the cramping. It's important to note that there isn't much research on how to ease early pregnancy cramps specifically, but many period cramp relief strategies focused on reducing pelvic pain may help.

Warm bath

One of the most effective ways to treat cramps is to take a warm bath. Warm water will help soothe the pain in the abdominal region and relax your muscles. One thing to remember about using heat to ease the cramping is to make sure the bath water is not too hot, as very hot baths (or heat packs) aren’t recommended during pregnancy. 

Prenatal yoga

Alternatively, you might want to try some prenatal yoga stretch poses to ease the discomfort. A small study found that people who practiced mindfulness-based yoga in their second trimester reported less pain and experienced improved comfort in early-mid pregnancy [13]. So if you think you might be pregnant, there is no harm in starting to build these kinds of healthy habits now!

Yoga offers gentle movement of the body that stretches the muscles and promotes relaxation, which can relieve any pain you might experience. A few great prenatal yoga poses to try are:

• Happy baby : Lie on your back and bend your legs at the knees. Lift your legs to hip height and pull them towards your chest. With your hands, hold onto your feet. You might gently rock side to side. This pose helps relieve the tension in the hips.
• Malasana (yoga squat): Stand up and reach your hands to the ceiling. With an exhale, circle your arms down and slowly lower yourself into a squat. Go as low as you can without feeling pain or discomfort. This pose helps open up the pelvic area.
• Child's pose: Get on all fours. Bring your toes together and open your knees wider. Push your pelvis back to rest on your toes and stretch your arms in front of you. Rest your forehead on the mat between your arms. You might add pillows and blankets under your pelvis and between your legs to make this more comfortable.

Painkillers

If you think you may be pregnant, you should avoid taking certain painkillers and anti-inflammatory medications like aspirin or ibuprofen, as they may increase the risk of early miscarriage and are not considered safe to take without the supervision of an HCP during pregnancy [14].

Consider switching to pregnancy-safe painkillers instead, such as acetaminophen (paracetamol), which is considered to be the safest OTC pain reliever for people who are pregnant [15]. Always check with your HCP before taking any medication, including herbal remedies, if you suspect you may be pregnant.

Other early signs of pregnancy

This early in the journey, it’s likely that any symptoms you experience are actually influenced by the hormonal shifts of the luteal phase, not yet of a developing pregnancy. However, if you suspect you might have experienced implantation cramps, look out for these early pregnancy signs in the next couple of weeks [16]:

• Missed or lighter period: You might miss your period completely, or it might be lighter than usual [12].
• Feeling sick: You might experience "morning sickness" and feel nauseous or even vomit. Despite the name, it might happen anytime during the day, not only in the mornings.
• Extreme fatigue: You might feel more tired and fatigued than usual.
• Sore breasts: Due to hormonal changes, you might notice your breasts change in shape and size and become more sensitive than usual.
• Peeing more often: You might feel the need to urinate more often and even wake up during the night to pee.
• Change in food and drink preferences and unusual cravings: You might find that certain smells and tastes repulse you, and you might experience strong cravings for particular foods that you haven't had before.

It's important to remember that everyone's bodies are different. That means that you might experience these early pregnancy symptoms, or you might not. You might experience more symptoms or fewer symptoms than your friend did, but that doesn’t mean there is anything wrong with your pregnancy or your body.

When to see a doctor

If you suspect that you might be pregnant, it might be a good idea to take an at-home pregnancy test. You can get them at your local drugstore without a prescription or order online. The best time to take a pregnancy test is right when you notice your period being late or about three weeks after having unprotected sex if your cycle is very unpredictable [17]. Note that you can test earlier, but there is a chance of a false negative result if pregnancy hormones levels aren’t high enough to detect the pregnancy. If the pregnancy test is positive or has a faint line, you should book an appointment with your OBGYN so they can confirm the pregnancy, perform all the early pregnancy checks, and run some tests.

Sometimes, light cramping and bleeding might not be due to implantation or your period. Other conditions have similar symptoms, like early miscarriage or ectopic pregnancy. Ectopic pregnancy is a medical emergency, and early signs include cramping and bleeding that might be similar to implantation cramping and bleeding. However, in the case of ectopic pregnancy, the symptoms tend to last longer and worsen over time [18].

If you suspect your cramps and bleeding might be due to miscarriage or ectopic pregnancy, contact your doctor as soon as possible.

Plan pregnancy with Natural Cycles

Natural Cycles is an FDA Cleared app that can help you understand your cycle better and aid you on your journey to planning a family. You can easily track your menstrual cycle and log symptoms like implantation cramps (and more). Our temperature-based algorithm is able to predict your most fertile days and ovulation window, so you are always aware of what's happening in your body.