Approximately one quarter of all pregnant women will experience bleeding at some point during their pregnancy. This often occurs in early pregnancy, around the time the woman should have had her menstrual period. This can also happen around the time her second or third menstrual period would have been due. Bleeding of this type is usually irrelevant and nothing to worry about.
Bleeding is also common after intercourse (contact bleeding) where small blood vessels can be slightly damaged in the cervix. This is also harmless, and is caused by the increased blood flow to the area.
As long as the bleeding is not accompanied by pain greater than a normal menstrual type pain and it is not too strong, it is probably due to hormonal changes in your body. In most cases the bleeding will quickly stop by itself.
Bleeding in early pregnancy can also result from a pregnancy outside the uterus (in the fallopian tube). If you do experience bleeding with pain which is worse than menstrual type cramping, you should consider seeing a doctor to ensure it’s not an ectopic pregnancy which can be very painful, harm future fertility, and in some rare cases even lead to death.
Bleeding in later pregnancy can be a sign of serious complications, such as a abruption of the placenta (where the placenta comes away from the uterus wall) or the placenta is located down at the uterine opening (placenta previa). These complications, however, are rare.
In late pregnancy bleeding can be a sign that labour is about to start.
If you are experiencing heavy bleeding or pain, or are worried about the cause of a bleed, contact your doctor or midwife.