PCOS and Gestational Diabetes Insight

Ok so, I have been thinking a lot about the chance of me having gestational diabetes this go around. I have had PCOS for almost 5 year. I didn't have it before my last pregnancy. I already have insulin resistance and I take Metformin for it now, so I just feel like I'm more than likely going to develop GD if I haven't already. Right now I'm only 12.5 weeks, and I start with a new OB next week (from fertility clinic). Does anyone have any insight on this? If you have insulin resistance did you develop GD? And what was treatment plan if so?