Flashing lights in vision...sign of preeclampsia?

I am 35&4 and just experienced flashing lights in my vision. It was almost like little lightning bugs flying around. It lasted like 30 seconds then went away. I have had perfect blood pressure my whole pregnancy...my appt on Tuesday I had high blood pressure when first checked but when they checked at the end of my appt it was perfect again. My hands and feet started swelling about a week ago, but the doctor checked Tuesday and didn't think they looked too bad. Is this just some weird thing or does it sound like preeclampsia? She told me the symptoms are severe swelling, headaches, and spots in your vision.