Ay, mama, at 31 weeks na, that persistent cough needs checking talaga, lalo na kayo're heavily pregnant na. Please see your OB or go to the clinic kundi to rule out anything serious, para sa peace of mind ninyo both for you and baby.
A few of us moms went through coughs during pregnancy, and ang hirap talaga because you can't just take anything, diba? Your doctor will know exactly what's safe for you and baby at this stage. Laban lang, mama, almost there na kayo!