Hi mama! Congrats sa 26 weeks!
Okay, para sa any medicine or herbal supplements habang pregnant, kailangan mo talaga makonsulta muna with your OB, kahit natural or herbal pa yan, para sure na safe for your baby. Hindi ako makakapag-recommend ng lagundi or kahit anong supplement without your doctor's go-ahead, kasi bawat pregnancy is different.
If your cough is really bad na, please message your OB agad or go to your clinic, they'll know what's best for you at 26 weeks. A few of my mum friends had coughs during pregnancy, and their doctors helped them find safe options, kaya don't worry, may paraan!
Take care, mamsh!