If you're on a narcotic for chronic pain & you get pregnant, what generally happens?

I'm going to see my OB-GYN on Monday, but I wanted to do some research too. I've been on codeine for scoliosis pains for the last couple years (Since 2012 maybe?) My doc prescribed me 30mg/day, but over the years my tolerance went up and now I need 165-180mg for it to work. I don't take it every night, I would if I could but because my family doc refuses to up it or change meds, I basically run out in 2 weeks & then have to wait 2 weeks for more.

After I ovulated & got my BFP, I quit. I have almost a full bottle of codeine in my bathroom... but skip ahead 13 days and now I'm feeling so sore & miserable! I'm fatigued and less active (which my spine hates). I have cramps, sore lower back & round ligament pain so going to work & being active sucks too. My family doc looked up codeine on motherisk.org & said it was fine, just to get off it toward the end to avoid baby being dependent on it.

But when I got home & read it for myself, it said it was okay in "therapeutic doses." Which probably means 30-60mg and not 165-180mg per day... Has anyone else been in a similar situation with codeine or similar opiate?