metformin and pregnancy

I am currently pregnant (4 weeks and 5 days) but miscarried in June 2018.

Both the last pregnancy and this pregnancy, I conceived with the help of metformin and clomid to induce ovulation. For my last pregnancy, my GP told me to stop metformin once she found out that I was pregnant, and I did. However, recently, I have read from many sources that continuing with metformin during pregnancy may help prevent miscarriages. I have PCOS and had gestational diabetes/insulin resistance from my first pregnancy. I know that most miscarriages are not preventable (due to genetic/chromosomal abnormalities), but I also know that sometimes it could be due to diabetes/PCOS/hormonal imbalances. We're just trying to figure out what to do best to prevent another miscarriage, if possible.  Should I be continuing metformin?

What has people's experiences been re: staying on metformin during pregnancy? Why did my doc say to say stop last time?

I'm currently still on metformin and will see the doc on Monday.

Any thoughts would be appreciated!