Spontaneous abortion usually occurs in the first trimester. Sometimes it happens in very early stages, and the woman does not even know that she was pregnant. Due to the delay, she may think that conception has occurred, but soon bleeding occurs, which can be confused with menstruation.
The threat of miscarriage may appear later, when pregnancy has already been confirmed. Bleeding in the first trimester is always a reason to immediately consult a doctor. In many cases, spontaneous abortion is a reaction of the pregnant woman’s body to dangerous chromosomal abnormalities and other fetal malformations that are incompatible with life6. However, there are also situations when the threat of miscarriage occurs due to hormonal imbalances or other reasons that modern medicine can eliminate and ensure the birth of a healthy baby.
The answer to the question of why menstruation occurs during pregnancy after several weeks without menstruation may be associated precisely with the threat of miscarriage. In such a situation, you should definitely consult a doctor and do it as quickly as possible.