Hi po! That's great na nag-consult ka na with your OB, honestly that's the safest approach talaga. A few of us mums have tried Vicks Formula 44 during pregnancy kasi it has dextromethorphan, which is the cough suppressant na generally okay for preggies, as long as you avoid ones with iodine. One of my mum friends swears by it para sa persistent cough, at she said it really helped her sleep better without worrying too much. Since your OB prescribed it specifically para sa'yo, I'd say you're in good hands, just take it as directed at mag-monitor lang kung paano ka nararamdaman. But definitely check back with your doctor kung may concerns or if the cough doesn't improve ah. Take care po!