Early Period: Causes, Symptoms & What to Expect

Question
I'm 22 and I have no children. My last period was on February 7. I am very regular but like twice a year I will have period that starts earlier then when I am supposed to. I'm not on any birth control. On Monday, Feb 20, I had sex with my boyfriend and we had protected sex and always do. I have been kinda stressed this week. And this morning I started my period. It's very light but my stomach hurts but not that bad. I'm not sore or anything but I'm 2 weeks early. Last time I started though I was lighter than I usually am. Is there reason why I have started early? Am I possibly pregnant? Thanks~Amanda

Answer
If you have a normal 28 day cycle (from the first day of your period until the first day of your next period) ovulation occurs on cycle day #14. YOu can only conceive if you have unprotected sex on cycle day #13, 14,15, or 16. If your last period started on February 7, you would have ovulated on February 20 and could have conceived if you had sex on February 19,20,21, or 22. If you did conceive at that time, a pregnancy test would not show a positive result until 14-21 days later. The best time to take a pregnancy test is seven days after missing your next period. You were due for your next period on March 6. Therefore, if you do not get a normal period by March 13, take a pregnancy test. Sometimes, if you are pregnant, you can have "implantation bleeding" around 8 days after conception.The bleeding that you are having today may merely be "ovulatory bleeding", which can occur around the time of ovulation.  I doubt that you are pregnant.