Tylenol with codeine???

I'll start off by saying I have a herniated disc and it is very painful. Before we became pregnant I was issued my medical marijuana card by my primary care physician in place of opiates which I was very against taking. When we found out we were pregnant I quit smoking. it wasn't as bad as I thought it would be quitting when I previously had to smoke atleast 3 times a day to keep pain free. Well now that I'm 13 weeks 6 days and am getting a little tummy. My back pain is out of control!! I cried today it hurt so bad. my doctor prescribed me acetami/codeine 300 and told me it is safe till the end. I trust her. But I am a unsure on how even small amounts of codeine will affect my baby . my questions are has anyone else been prescribed acetami/codeine 300? what do you think? And does anyone have other suggestions to help me with my pain? I really just want what is healthiest for my baby but I can't seem to get this pain under control with out smoking and no I haven't smoked even when I've been crying in pain. Please no rude comments I am a sensitive person to begin with lol happy and healthy pregnancies to all ☺