I am on metformin and was told to come off it by my FS when i fell pregnant. The pregnancy ended in mmc, but who is to know why that was. No two Dr's that I have spoken to have had the same opinion of metformin and whether you should stay on it or not. There are no official medical reports to prove that it lowers the risks and this is why they don't all have the same advice to give us. Not much help really. I don't know whether I would carry on taking it next time, or whether I will follow the advice of my FS again. I will be seeing him in a few weeks so will talk to him about this.
In answer to OP, i think we have to stay as positive as we can about our pregnancy, and whilst I will be cautious due to having had a mc already, I will try and enjoy every minute of any pregnancy that I have for as long as it does last.
Good luck xx