I have never had an issue with this but I tend to think better safe than sorry, KWIM? Most likely, you are fine but my coworker's cousin just had a baby with very well controlled gest. diabetes and he ended up in the NICU for 9 days trying to kickstart his little pancreas! GD can be extremely serious for you and the baby so, just to make sure, I would go ahead with the test. Good luck!