It depends on the reason you are taking metformin while pregnant.

I had to keep taking it during first trimester to help reduce the risk of miscarriage, and there was no way in hell I'd stop taking it for any reason then! If I threw up the tablets, I'd take an extra... But it was fairly obvious that it was a big risk for me when reducing the dose of metformin in my first pregnancy coincided with the death of my baby.

I'd stick with the panadol and gastrolyte and keep the metformin going... If you get too sick, definitely bother your doctor again.

BW