4 months pregnant and prescribed Tylenol with codeine?

I went to my primary care doctor this morning and it turns out I have an ulcer on my throat. She prescribed me Tylenol with codeine. I called my OB and they said it was fine to take in the second trimester. I'm still a little concerned as it does contain the narcotic. has anyone ever had problems with this medication in pregnancy or taken it with no problems? Thanks!