Hi, I was diabetic with my last pregnancy ( which was twins) 25 years ago. In those days they only gave insulin and diet. I had a normal delivery for both babies ....it was my 4th and 5 th baby.
I am now 59 years old , I think I am prediabetic but have never been diagnosed with it. I do my blood sugar rugarly nand have always tried to watch my diet by eating as low carb as I can. I have always kept vey active ie dog walking, gym , swimming etc.
If your diabetes is controlled then you should not have too big a baby, regular scans will be done to monitor that, don’t worry the metformin and insulin will not harm your baby. Just try and keep to a healthy diet and ask the midwives at the diabetic clinic for advice. Good luck