Talk to Gynecologist on Pregnancy With Diabetes

I am diabetic female 32 years, now pragnant 18 weeks, has gestational diabetes also, my doctor advised me to take 500 mg twice a day, i am fully controlling my diet also avoiding carbs as much as possible but my fasting sugar is always higher than 90 and random is always higher than 120, like fasting sugar is sometimes 120, 128, 99, 117, 132 and random sugar 164, 140, 135, 141, 136, 139, 101, 158 I am very much tensed about it. I have appointment to my doctor after 1 week so can anyone guide me is there anything to worry about? Or i should start taking insulin by my own with permission of my family doctor not gynaecologist , or should i wait 1 week and tell these readings to my dr then follow her what she says?