8dpo dizziness

I'm 8dpo and yesterday when working out (I do Jillian Michael videos at home and yoga, etc..So they're pretty advanced ) I got REALLY dizzy. like she does these circuits that you do strength, cardio,.then ab work. and as soon as I was off the floor after ab work I stood up and saw spots and got So dizzy. this happened every time after the ab part. this never happens to me. as I'm a pretty good workoutaholic Lol. could that be a sign of pregnancy? I also drank plenty of water. So I wasn't dehydrated. but I kept going even being dizzy. is that dangerous? should I stopped working out? I don't want to Because That's what takes my frustration out of the day!