Are you addicted to xanax or dependent on it? Meaning, do you take it in a responsible way and cannot stop because of the withdrawal symptoms, or do you take it in a irresponsible, abusive way? I think the approach to stopping would depend greatly on this.
If you're dependent, you can do a water titration, or the benzo water taper, to reduce your dosage safely. You can check out the Ashton Manual (Google it) for instruction on how to do that. You have to be careful with c/t with benzos. It's the equivalent of telling a severe alcoholic just to stop drinking, you can die from it.
Now, if you're addicted to xanax, that's a whole other ball of wax. Throughout my entire pregnancy I wrestled around with a xanax addiction and as soon as my son was 6 weeks old me AND him went straight to an NA meeting. I thought I was different because it was xanax and not an opiate or some other sort of drug. Boy was I wrong, it was like comparing a house cat to an alley cat, same darned thing. It was the best thing I ever done. Going to meetings gives you the support, and the steps starts the healing process, it'll help you drag the crap alll the way out the closet. It took me many years to get there because I thought xanax wasn't that bad. That stuff is the DEVIL.
Start your meetings now. You'll need it through your pregnancy. Don't worry about judgement from others because we have all been in a compromised position. The forums are awesome, but in early recovery you really need the face to face meetings to make it through.