Veronika, welcome and congrats on your pregnancy. I'm gonna give it to you straight though: that is not a "small" addiction. Actually, there in no such thing. Get honest w/ yourself, and get honest w/ your doctor. Do not change ANYTHING until you see your doctor. The baby feels whatever you do, so that means detox, which could lead to dire consequences.
Make an appt w/ your obgyn and be 100% honest. Take your ego out of it, it's for your baby. You can't shock doctors, they've heard it all.
Good luck and keep posting for support.
Are you getting these pills from a doctor? You need to talk with your OB about this. Stopping cold turkey can be harmful to that baby. Do what is right here. I would also recommend getting into some sort of recovery care. You need to deal with why you continue to use.