Ay nak, that's a serious concern, please go see your OB right away, okay? Bell's palsy during pregnancy needs proper medical check-up para ma-monitor ng doctor ang baby at ikaw together.
I haven't had it myself, but a few of us mums know someone who had facial paralysis during pregnancy, at super importante talaga na may expert guidance siya throughout. Your OB will know the safest options for you and baby, so don't delay, ha? Sending you strength, mama.