dizziness?

The other night I was out with a friend & we were standing in the store talking to my family members. I was talking & laighing fine. Then all of a sudden I got really dizzy &I they said my color in my face &I lips went away. I seriously thought I was gonna pass out. I checked my sugar &a blood pressure & both was perfectly normal. So I was wondering if that is a sign of pregnancy? Thanks in advance ladies.