I had intercourse last friday which is also my first day of regular menstruation. I got my period in the morning upon waking up. The intercourse was around in the afternoon. No ejaculation happened inside me, at least that I know of. At night, i decided to take nordette 21 (4 pills) and another 4 pills after 12 hours. On the following day, I got a bit paranoid and decided to take another 4 pills and another 4 after 12 hours and the following day, i still took the last pill. My period still went through for about 3 days and suddenly stopped. i was thinking it was the effect of the birth control. Is there a chance I could haveconceived? Today, i had some type of bleeding. The blood looks like the blood i normally get in my first day of menstruation, there were some red and brown to it. could this bleeding be withdrawal bleeding from the pills or implantation bleeding?