A1C Levels

I was dx with GD like 3-4 months ago. I’m 38 weeks this week. At first, I didn’t struggle with my glucose numbers either fasting or dieting numbers. Then, they started spiking so I’ve had to be super strict since. They checked my A1C like two months ago and it was great. Checked it again this week and it is still great, hasn’t changed. What gives?! I’m glad my A1C is great but why would I struggle with my numbers so bad but my overall blood levels be that great?