Hello Dr. I had my first menstruation on the 28th of April, it lasted till 2nd of May. On the 4th of May, I was sexually acitive with my boyfriend. To prevent pregnancy, I took an oral contraceptive less than one hr after being active. Today being 14th May, I saw that I was bleeding in the morning, at night, the bleeding stopped. Please from my above brief history is pregnancy possible to occur? Could it be that I was active during my ovulation day? Is the bleeding I saw classified as implantation bleeding? What should I do to prevent pregnancy if it is implantation bleeding?