Does clomid make cycles longer?


Hi all,

Started my 1st Round of clomid 50mg cd 5-9(Dec 26-30). BD every other day from last pill untill cd20. Had cd21 progesterone results were 5.5, which is low but indicated ovulation had occurred. The Dr said he suspects I ovulated between cd 13 and 15 because that's when I was experiencing the pain in my left side. But I got my first and only opk on cd19. At my appointment he also performed a internal ultrasound and said there was a cyst of my left side. I'm now on cd33 with no sign of af, took a hpt last wed which was a bfn. Could the opk been right and what was thought to be a cyst was actually a large follicle and ovulation occurred that day? Or does clomid just really make cycles longer? I'm so confused because I'm ready to start round two but there's no AF in sight!