Heavy Bleeding & Missed Period: Causes & What to Do

Question
I am 20 years old and I don't have any children. My last period was a few days late and started on May 11.  I've been taking the pill on and off for about 3 years. This past month I was late for my period and was worried about being pregnant because I wasn't very consistent with my pills last month and had unprotected sex. My period ended up coming a few days late but was very heavy and clotty compaired to usual. I also felt more run-down than usual, bloating, cramping, and my breast were very full and tender.  The next week I started a new pill pack and have been taking them consistently the past week. Yesterday I noticed that I had some break through bleeding, and the same thing this morning when I woke up. It seemed like more blood than just spotting, it was also a bit clotty.  Is it possible that I may have miscarried? I read up a little on miscarriages and asked a girlfriend of mine, but I would just like an experts opinion. Thank you,  

Answer
If your last period started on May 11, you would have ovulated on May 24 and could only have conceived if you had sex on May 23,24,25, or 26. If you do not  get your next period on time (June 7)  , wait until June 14 and take a pregnnacy test. If  you had been taking the pill, it is doubtul that you  could have conceoved. If you got your period on May 11, even if it was late, it is doubtful that you are pregnant. If you have any doubts, take a blood test for pregnancy. A value of less than 5 indicates a negative pregnancy test.