Ovulation on cd 7 or 8??

My husband and I have been ttc for two years. We just started another round of 100 mg Clomid. My period came and only lasted about 4 or 5 days and I took the Clomid days 3-7. I got an opk and started taking them the day my period ended. I got a definite bfp on cd7 & 8. Is that even possible?? I'm wondering if I have always just ovulated early and never knew it. Any info would be greatly appreciated! Thanks!