I was 17 and still hadn't started my periods at all. About a week after I lost my virginity I started having periods. why is that? Also I while I am on my period the first day I will bleed all day, the next day slows down, the third day is super super light and only bleed a little the entire day, it sill stop for a day then spot on the 4th and be over. I am now 23 and my periods have been like this since after I first started after losing my virginity at 17. Could I be infertile? Considering these two factors.