Hi, I've not taken metformin in pregnant as am type 1 but I research diabetes in pregnancy as part of my job and there is a huge amount of data on it safety in pregnancy.
The risks of not taking it and having high sugars are far worse than the risks of taking it which are absolutely tiny through all trimesters.
Metformin is also used to help some people with pcos to conceive so there is safety data in this cohort of patients too.
Can I ask, are you on it for type 2? If so your team should be able to give you lots of support and advice.
Let me know if I can help.
Good luck.
Jess