Metformin question

I know I need to ask a doctor, and I did I'm waiting to hear back so I thought I would try you lovely ladies and see if you had any insight, I have PCOS but I have pretty regular cycles and I take ovulation tests and they are pretty normal I get low, high, peak and then low readings. This is my question, do I need to take the metformin of I am ovulating and having periods? My OBGyn suggested trying it and to take OPKs. I have not been taking it because it caused me to gain like 10 pounds in 2 months. I stopped taking it, lost the weight and have normal cycles/ OPKs. But is there any other reason to take the metformin? Does it help with the conceiving and everything else or just the ovulation? I hope this makes sense, thank you for any help