Clearblue opk question!!

My husband and I have been TTC for about a year now. My dr put me on 3 months of birth control. I have all normal hormones, and I normal reproductive system. This was our first month TTC since going on the pill. I started testing with clearblue opk on CD 5. On CD9 & CD 13(today) I got a possitive opk. It doesn't make sense to me that I've had 2 possitives. Anyone know anything about this?