Anniversary rules: what are they?

The absence of menstruation often puts women on the track of a pregnancy. So when they think they are pregnant, but discover bleeding, they panic! What if it's an anniversary period? You have never heard of this phenomenon? Elie Lingerie offers you a catch-up lesson.

What is an anniversary period?

A pregnant woman's period is called an anniversary period when she has bleeding at the beginning of her pregnancy. It is actually metrorrhagia, unexpected bleeding that can occur between periods, during pregnancy or at menopause. It affects 1 in 4 pregnant women.

Why do women have periods during pregnancy?

Women do not menstruate while pregnant. In fact, menstruation is due to the elimination of the uterine lining (the endometrium) when the egg has not been fertilized. Anniversary periods are usually artificial periods, as they occur in women taking the pill. This bleeding can be caused by a decidual hematoma, a slight detachment of the placenta that will resolve on its own. It can also be caused by discharge from weakened vaginal walls. The cervix is more vascular during pregnancy. Harmless bleeding may occur after a gynecological examination or sexual intercourse.

When does an anniversary period occur?

Contrary to what the term "anniversary bleeding" may imply, this bleeding does not necessarily occur when your period should have arrived. It can occur throughout the first half of the pregnancy. In the case of pregnancy denial (the pregnant woman does not know that she is pregnant), the duration of anniversary bleeding varies. If the woman continues to take the pill, the contraceptive may continue to cause an artificial period.

How do you recognize when an anniversary period is coming?

The most important issue with anniversary periods is how to recognize them. There are several signs that can put you on the trail.

A change in color

Every woman's period has a different color. However, red bleeding should alert you. Brownish or blackish discharge is also a concern, especially if it is accompanied by pain. When the discharge is slightly pink, there is a good chance that it is an anniversary period.

The onset of pain or cramping

Anniversary periods are usually painless. However, sometimes you may experience cramping or tightness. If you experience painful bleeding, see your doctor quickly. This may be a sign of a miscarriage or an ectopic pregnancy.

Reduced menstrual flow

Anniversary periods last one to two days. This bleeding is not heavy.

Bleeding caused by implantation

When the fertilized egg settles on the lining of the uterus, it is called implantation. This occurs about 10 days after fertilization, which is about the time your period should have arrived. Sometimes implantation causes bleeding, which can explain the "anniversary period".


Pregnant women usually rely on their periods to tell them if they are pregnant. However, if their egg is fertilized and implantation causes an anniversary period, they may not be able to detect their pregnancy. When you have your period (or think you are having your period) and are experiencing nausea, get tested to see if you are pregnant.

Is blood loss always related to an anniversary period?

Blood loss in the first trimester of pregnancy is not necessarily related to the anniversary period. Bleeding in pregnant women should always be seen by a doctor. It can be a sign of a complication such as an ectopic pregnancy, a miscarriage or a molar pregnancy (abnormal development of the placenta).

How can you tell the difference between an anniversary period and a miscarriage?

A heavy anniversary period that lasts more than two days or is bright red could be a sign of miscarriage. On the other hand, pain such as cramping or tightness is not necessarily a sign of miscarriage and can occur during an anniversary period.

Is it possible to have a negative test during an anniversary period?

It is quite possible to have an anniversary period after a negative test. In early pregnancy, tests are not reliable. If you have nausea and tender breasts, but your test is negative, your period may be an anniversary period resulting from nesting. Only a blood test will give you a reliable result.

Bleeding during pregnancy is always worrisome, but it can be harmless. This is the case with anniversary bleeding, which can occur during the first trimester of pregnancy. To make sure that you are suffering from this phenomenon, which has no impact on your pregnancy, consult your doctor. A heavy period, or one accompanied by fever or pain, may be a sign of miscarriage.

FAQs about menstrual bleeding

How can you tell the difference between an anniversary period and bleeding?

Anniversary periods are light in color. Bright red or blackish bleeding is more likely to suggest a miscarriage. Similarly, heavy periods are rare. When the flow is heavy and lasts for more than 2 days, it may indicate a problem with the pregnancy. Severe pain or a fever over 38.5°C should also alert you and lead you to seek help.

What color is the bleeding during pregnancy?

Anniversary bleeding is light pink in color. It may be slightly brown or red but should not be accompanied by pain or fever. To be sure it is a period, consult a doctor.

Is it possible to be pregnant and bleed?

Les informations issues des articles présents sur le site sont des informations générales. Bien qu’elles aient été relues par des professionnels de santé, ces informations ne sont pas exemptes d’erreurs, ne constituent pas des conseils de santé ou des consultations et n’ont pas vocation à fournir un diagnostic ou proposer un traitement. Ces informations ne peuvent, en aucun cas, se substituer à un avis médical et ne peuvent pas remplacer une consultation auprès d’un professionnel de santé. Pour toute question, nous vous invitons à consulter votre médecin.