Sis, I haven't personally kena Bell's palsy during pregnancy, tapi one of my mum friends did experience facial weakness masa third trimester and it was honestly scary for her. Definitely kena see your doctor or OB ASAP to rule out anything serious and get proper treatment, because pregnancy + neurological symptoms needs proper medical eyes on it, ye? Beliau kena referred kat neurologist and with treatment dapat recover, alhamdulillah. I know it's worrying tapi doctors boleh handle, just jangan delay consultation. Hope you're okay, do update once you see the specialist, sis!