Recent fertilization: If you notice a small amount of bleeding about a week to 10 days after conception, it may be due to the implantation of the egg in the lining of the uterus. This is nothing to worry about.
Pap smear: It's not uncommon to bleed after a Pap smear or pelvic exam, which in many practices is conducted between the sixth and 12th week of pregnancy. Spotting may occur within 24 hours after the visit and usually goes away within a day.
Having sex: During the second and third trimester, your cervix becomes swollen because of the increased blood supply in the area. As a result, vigorous intercourse may cause spotting.
Infection: Some women have cervical bleeding because of an infection, usually a sexually transmitted disease such as chlamydia. In this case, the underlying condition needs to be treated.