15 dpo and still BFN

Stephanie
This is my first clomid cycle and I am currently 15 dpo. My Lh phase is usually like clockwork and I have never been late. I temped and used OPK to tell when i ovulated and I am still getting BFN's. Did clomid make anyone else's cycle longer on the back end is there still hope of a BFP? Thanks ladies!