The best dose of Clomid is the smallest does that makes you ovulate. If you don't ovulate on 50 mg, then no problem to go to 100 mg. But, I think it's weird to start with 100 mg, especially if you are ovulating on your own. I'd start on 50 mg if I were in your place. There are side effects like thinking your uterine lining and reducing cervical mucus, also risk of over stimulation, and higher dose = more side effects, so you don't want a higher dose than you need.