Provera/Clomid/Ovulation Q's....

My AF is 11 days late and I'm on day 3 of provera. After going off bc YEARS ago, I'm starting my first cycle of clomid as soon as AF comes. Any major side effects, personal experiences or tips for Clomid? And what type if opks do you use? I have been buying the cheapos from dollar tree but just found out about the bulk test strips. Is there an ovulation tests it TTC for dummies? I don't want to waste this month by doing anything wrong!