You should get in touch with your OB/midwife and get them involved in this situation. Abrupt withdrawal will be very unpleasant to you, but it could be damaging to your pregnancy. The OB or the midwife will be able to refer you to an addiction specialists who treats other pregnant patients with Suboxone or Subutex. I know that either of these medications are safer in pregnancy and nursing. They can then taper you off of it gently as your pregnancy progresses which will allow your baby to be weaned off slowly and safely. This way, by your third trimester or certainly by the time of the delivery both you and the baby are clean and ready to start healthy bonding and nursing.
The OB/midwife will also be there to guide you though good pre-natal care, healthy nutrition, smoking cessation (if necessary), etc..
Good luck to you, motherhood is a career full of joys and pain, but we all do it for the joy of it...
P.S. Please read my blog on Pregnancy and Addiction by clicking on name in blue and then on blogs.
U need to go to a clinic and get subutex i have been on it my hole pregnancy and my baby is healthy its the only thing i couldve done in my eyes to b in recovery n i feel great hope the best for u