Spotting at 21 days

I don't know what to think.. this started yeterday at 21 days into my cycle... I have no period symptoms except I'm so exhausted and today I had a dizzy spell while driving and it made me feel like I was about to pass out.. now idk if that has anything to do with the spotting.. but I've been told is could be ovulation spotting but I had my positive opk like a week ago. Anyone think it could be IB?

My spotting hasn't gotten any heavier at all.. and it comes and goes.