Does a positive opk mean I definitely ovulated?

Briolette • 💚💙Rainbow baby due 3/10/16 💛💜
Hi ladies! I have PCOS (mild according to my doctor) and possibly endometriosis. I know that means it's possible I'm not ovulating. If I buy opks and it shows positive, does that mean I am ovulating? Or can those give false positives? Just trying to figure out what to do here... I've had 3 unsuccessful cycles so far. Thanks all!