Metformin !

I'm 21 years old I was diagnosed with pcos not really sure if it's a real diagnosis more like "she has some symptoms lets go with that."Okay so I've been on metformin since April 10th at first I was taking two 500mg pills daily and just recently my dr increase it to four 500mg daily. I still don't have a period. I'm not sure if I'm pregnant.  To be honest I really don't know what to expect out of this. . .  If anyone has any answers or can just offer wise words I would truly appreciate it.