Hi, I have had normal periods since my cycles began. I am able to track them with period trackers because they come every 28 days. I was on birth control for 7 years and stopped taking it last November in hopes to get pregnant. I know when I ovulate because I cramp and have the milky discharge. This last period came almost 2 days late which is very unusual..I began spotting then on night 2, I woke up and my pad was almost over flowed with thick blood clots...There were alot of clots in the toilet too. Then i spotted for a while and then had a normal period. What could have caused this?