Three out of ten women experience implantation bleeding during the first few weeks of pregnancy. Basically, it is a light bleeding that occurs between 10 and 14 days after conception and occurs as a result of the implantation of the fertilized egg in the uterine wall. In some cases, this bleeding can be confused with a menstrual period, but sometimes it is so light that it can even go unnoticed. We explain why this bleeding occurs, how to identify it and what you should do if it occurs.

Why does implantation bleeding occur?

Embryo implantation is the process by which the embryo implants itself in the endometrium. It all begins after fertilization, when the embryo begins to move from the fallopian tubes to the uterus. Upon reaching the uterus, it adheres to the endometrial tissue, the inner wall that covers the uterus, which will allow it to absorb nutrients from the mother’s body for its proper development. This happens around the seventh day after fertilization, although it will not be until around the fourteenth day that they will have nested. 1 Weird Habits Of Breastfed Babies.

As the endometrium is a highly vascularized tissue, prepared precisely to “feed” the embryo, there is a probability that some vessels will rupture when implantation occurs, causing blood loss known as implantation bleeding. It is a completely natural phenomenon that also favors the union of the embryo to the future placenta thanks to the formation of new blood vessels that develop to take the place of those that have been broken.

5 keys to identify implantation bleeding: How to differentiate it from the menstrual period?

Many women often confuse implantation bleeding with their period. However, although it is true that many times it can coincide with the date of the menstrual period and lead to mistakes, in reality this bleeding has characteristics that easily distinguish it from the period.

1. intensity

In most cases, the intensity of implantation bleeding is usually very light. Usually, it is just a few spots, although sometimes it can be more intense, in the form of light bleeding similar to the one that appears at the beginning of the period. It is not usual for heavy bleeding to occur, in which case it is recommended to see a doctor, especially if it is accompanied by other symptoms.

2. Duration

The duration of implantation bleeding tends to vary quite a bit from woman to woman. On many occasions, the bleeding lasts only a few hours, in which case it is usually just a few spots or a very light bleeding that disappears quickly. However, the most common is that this light bleeding lasts between one and three days.

3. Frequency

The frequency of implantation bleeding is highly variable. In most cases , the most common is that the bleeding occurs intermittently, which allows it to be easily distinguished from the menstrual period. Although it can occur sporadically in some women, this type of bleeding does not usually occur constantly.


Color is one of the most identifying characteristics of implantation bleeding that allows it to be distinguished from the usual menstrual period. In general, this bleeding presents a very intense coloration, with a dark red color reaching almost brown. This is because the blood has to travel a long way from the endometrium to the vagina, during which time it loses its color. Hence, it is not usually a bright bleed.

5. Density

Implantation bleeding is usually much lighter in density than menstrual period blood. This is because it comes directly from blood vessels, while menstrual period bleeding also includes remnants of the endometrial epithelium, which gives it greater density and makes the appearance of clots frequent, which is not common in implantation bleeding.

Other symptoms associated with implantation bleeding

Sometimes implantation bleeding occurs alone, but in many cases it is accompanied by other symptoms, usually associated with pregnancy. Among the most common symptoms are:

  • Colic. Implantation cramps are nothing more than a mild and intermittent discomfort that mainly affects the lower abdomen, similar to the discomfort that occurs during the menstrual period. It takes place during the process of implantation of the embryo in the uterus and usually lasts about two days.
  • Abdominal spasms. They are a consequence of the changes that the body, and especially the uterus, undergoes during the implantation process. Basically, it is a kind of contraction of the muscles of the abdomen, followed by cramps, which occur sporadically during the implantation of the embryo.
  • Sickness. This is one of the most common symptoms during embryo implantation. It usually appears shortly after the bleeding, although it can sometimes occur at the same time. Although it can appear without any trigger, the most common is that it is exacerbated by the presence of certain strong odors.

Stomach discomfort, such as constipation or diarrhea, can often also occur, which is related to the hormonal and physical changes that begin to take place in the woman’s body.

Is implantation bleeding dangerous? What should I do if it occurs

Implantation bleeding is a completely natural process that does not pose a risk to the pregnancy. So far, there is no evidence linking it to a higher risk of miscarriage or other complications during pregnancy, so once the bleeding is over, the pregnancy should continue its natural development. In most cases, no additional care is usually required as the bleeding goes away on its own after two or three days.

However, whether you want to make sure that it is implantation bleeding or if you want to learn more about the guidelines to follow while it lasts, you can consult your gynecologist, who will be able to explain in detail what to do about your symptoms. Likewise, if you present very abundant and continuous bleeding or if it is accompanied by blood clots, you should visit the gynecologist to make sure that the implantation has occurred successfully and that there is no problem that affects the pregnancy.