Dizzy spells?

I'm 26 weeks and 3 days. About an hour, hour and a half ago, I started to experience slight dizziness. It would come on quickly and go away quickly. I'm going Master of the Obvious here for a second, but I think it's low blood sugar. I haven't eaten as much or drank as much water today as I normally do. But even after having a yogurt and some water, I'm still feeling it a little. I don't feel like I'm about to faint or anything. Normal for this phase? Could it be anything other than low blood sugar? I'm a hypochondriac and I feel like this stuff always happens at night or on the weekend when the doctor's office is closed. 😰