Hi. What's the difference between a period and pregnancy bleeding? Possible sex in oct, tender breasts before period, spot before, bleeding lasts 4-5 days?

Preg vs. not preg. Period, or menstrual bleeding, occurs because a woman did not become pregnant and her body is essentially resetting itself to try and become pregnant the following month. Bleeding that occurs in early pregnancy is often due to the implantation of the embryo into the uterine lining and usually resolves in the first 2-3 months of pregnancy. Hope this helps.