Sis, please see your doctor or go to the clinic asap, ang 90/50 ay mababa talaga, at hindi yan basta normal na hindi lang kainin o inumin lang ma-solve. A few of us mums have had low BP before, at seryoso, kailangan ng proper check-up para malaman kung ano ang dahilan. It could be dehydration, or something else na kailangan talagang i-monitor ng doctor. Don't wait on this one, ha, better safe than sorry para sa'yo!