I and my husband tried to conceive on September 9 , which I found as my fertile day . My expected period date is on 24 September. But on 18 th September morning I got up with heavy back ache and I found that I was bleeding.My period was not much early since then.Because of the date it came and also the way it came I felt it as unusual.But from the next day I felt it as normal period with heavy stomach and lower back ache. But when I searched internet I found that there is something called implantation bleeding when pregnant. Now I am confused whether it is mensturation or implantation bleeding. I am anxious ti know whether I am pregnant... can any one answer my doubt?. help..