Hello Dear
I've just started on Provera to bring on a period and Clomid on days 3-7 of my period. I have a GREAT OBGYN who's helping my husband and I TTC. Here's what she told me...
Your miscarriage rate is not increased just because you have PCOS. Depending on the severity of your PCOS, most women have great success with the provera/clomid or metformin/clomid combination. My OBGYN told me there was a great chance of us conceiving within the first three cycles so long as the dosage was correct for me.
Multiple births? You have an 8-10% chance of multiples, but if your doctor is closely monitoring your ovaries, he will probably notice if you have multiple healthy eggs that will release on the same cycle and can let you know ahead of time, then you and your hubby can decide whether or not to TTC that month and your doctor will adjust your medication accordingly. The chance of multiples is really only if your Clomid dosage is too high - allowing too many healthy eggs to be released at once.
About the weight - that's a huge side effect of PCOS. The clomid, over time, should actually help you better manage your weight. I know for me, it was a HUGE relief to hear that I could lose the weight. PCOS, as you know, is not an ovarian disorder, but a metabolic disorder that wreaks havoc on your ovaries. Your body cannot process sugars properly which makes you gain weight and it becomes next to impossible to lose it unless your system is brought back into balance with medication.
Hope this helps! And don't ever be afraid to ask your doctor all of those questions, that's what they are there for

There really are no stupid questions.
Praying for you and your soon to be baby!