I agree with Spade you should cut back on the Xanax, but you should be fine with the hydrocodone. As you pregnancy progresses you might want to seek some alternitive pain relief options so that you can cut back on the meds a little bit. Maybe massage or accupuncture (sp?).
Good luck in your pregnancy.
Xanax is a Class D drug which means it has been shown that it can have an adverse effect on developing baby - you really need to do a risk-benefit analysis but typically, any Class D medication should be avoided during pregnancy. Ask your doctor about Vistaril - this is a much safer drug that can help w/ anxiety/panic/sleeplessness during pregnancy and would be preferable to Xanax. There are also antidepressants that might be useful to help with some of your symptoms during pregnancy.
Hydrocodone and percocet are Class C medications which means that studies in animals show it has no adverse effects on fetus but no well-controlled or documented studies have been performed in humans. Class C drugs are often prescribed to pregnant women when benefits outweigh the risks which sounds like it is the case w/ your pain management.
The Xanax is really the one to watch out for. How much do you take and how often? This is not something that can be stopped abruptly due to dependency and severe withdrawal symptoms.