You can also check with a pharmacist, after all they actually went to school to study medication.
If u take then as prescribed and your dr. knows I wouldn't worry I am taking lortab for my migraines and it is ok. I also worry about my baby being dependant and think I am going to try to stop a few months before delivery just to make sure but I wouldn't suffer in the meantime. Your dr may adjust your meds.
You are best to talk to your doctor about that. I would definitely talk to him/her before you take any strong medication such as Percocet...