Norco 5/325? PLEASE help.

I posted a couple of days ago about pain in my side which turned out to be kidney stones. Because I’m almost 35 weeks pregnant there’s not much that I can do or that the doctors can do, except hope that they all pass. They prescribed me phenergan and Norco 5/325. Ive been too scared to take the Norco because it is a narcotic drug, with me being so far along in this pregnancy. However, I gave in tonight and took one. I’d like to believe the ER doctor wouldn’t give me anything that would harm my baby and my OB said to only take it if I ABSOLUTELY needed it

With that being said, does anyone know how this will affect my baby? I know it was only one pill but this is my first pregnancy and I worry about every single thing I take.