Late Ovulation on Clomid?

Ashlyn
I'm on my first round 50 mg of clomid days 3-7 and I'm at CD15 and all OPKs have been negative. I have pcos so sometimes I don't get AF at all and don't ovulate so idk what my norm is but I read somewhere that some people ovulate way late and especially on clomid. Have any of you  ovulated late on clomid? 
I may just be looking at a failed first round but I'm trying to be positive :)