What number is consider high for gestational diabetes? Because i check for 2 mths its 4 to 6.

Readings of 4 to 6 do sound like they are within a fairly common range, but the target numbers can differ depending on whether it is fasting or after meals. It would really be good to clarify with your gynae or doctor what the specific targets are for your case, since they will have your full picture. Please don't stress yourself out too much, just bring your readings log to your next appointment so they can advise you properly