Hydrocodone

I am 34 weeks almost, and I have a wisdom tooth that is literally rotting out of my mouth ( I know, way disgusting) and an exposed nerve in the tooth next to it. ( I have always brushed and flossed, but unfortunately shit teeth runs in my family) if anyone has ever had an exposed nerve they know hat it is WORSE than labor pain. Seriously. I have some left over low dose hydrocodone/acetaminophen from before I became pregnant. I almost passed out from the pain earlier so I took one. I tried Oragel and other stuff but it wasn't even touching the pain at all.  I also feel guilty for taking one, but it can't hurt if I'm not consistently on it, can it? One can't cause harm to the baby can it? Has any one else had to resort to pain killers?