So confused!

So me and my partner have been ttc for over 2 years i got diagnosed with pcos put on metformin and told to lose weight as my problem was i didnt ovulate. So far ive lost a stone and a half. Tues was my ovulation day and i had twinges so i picked up an OPK and it was positive id actually ovulated! Firat time in 2 years i was so excited! we had sex that night but then wednesday afternoon i noticed blood when going to the toilet only a little pinkish colour when i wiped but the last couple of days ive had cramps and the blood is still there but red and a little more now, im wondering if i have started my MC!? I cant find anybody else its happened to so im confused how can i ovulate then come on a day later?