TTC w/PCOS Clomid help!!!

I was prescribed Clomiphene citrate today. 50mg. 15 pills. (for 3 months) Plus 1 refill. I have been TTC for 3 years with use of Metformin off and on for that time. But can't handle a high dose (BAD side effects) I do have my period on my own. Pretty regular with a plus or minus a few days window. My question is...when do I start taking the clomid? Should I take any Metformin with it? Will that increase my chances? Any information or stories would be greatly appreciated! Thank you, ladies!