the same happened to me a couple weeks before my kid was born,(i always had low BP, but its normal since i never feel tired or anything) i didnt worried, but my inlaws made my hubby take me to the doc, and i was fine, so i just tought i might have been unconcious nervousness because i never was nervous, or maybe like they said it was just the baby giving me some advice he was coming soon

dont worry, but DO check up since we all are different, but i hope its nothing.