Mama, I'd really suggest you call your OB or go to your clinic soon, hindi normal kung may headache kasama ang low BP, kaya mas better na i-check agad. Your doctor needs to see this, lalo na kayo at the precious one inside.
Alam ko medyo nakaka-worry ang ganyang pakiramdam, one of my mum friends had similar symptoms at ang OB agad siyang tinawagan, at okay lang naman eventually but it's always best to get checked right away. Huwag mag-antay na lumala, sis!