Always feeling faint

I'm 37 weeks pregnant and I am constantly feeling like I am going to pass out. I get super lightheaded and feel like I could hit the floor at any second. It's a constant feeling whether I'm standing, sitting or laying down. I get so dizzy to the point I feel drunk when I'm laying in bed at night.

I've always had great blood pressure, I get checked two times week when i go for my NSTs. I have gestational diabetes and my blood sugar is never too high or too low, I'm pretty well managed by watching my diet.

I mentioned to my OB at my last appointment on Friday that I have been feeling this way. She said she wasnt sure why I was feeling this way and that nothing in my report seemed alarming. All she said was to try not to be alone when I feel that way and to make sure I hold the railing when walking up and down stairs. She wasn't very helpful at all. She isn't a provider I see very often. (My OB office has about 7 different providers and I never see the same one continuously so I'm kind of bounced around between 3 or 4 different doctors in the building.)

Should I not be concerned about feeling this way considering shes not concerned? Or should I call my OB office in the morning to see a different provider? I just dont want to be overreacting if its nothing but I just dont feel right. My body gets really heavy and sluggish, I get lightheaded and feel like I'm going to faint all day every day. The feeling increases throughout the day but I constantly feel like this.