I took my birth control regularly and took a zpack had unprotected sex took plan b pill should i be worried?

No, don't worry: First, the birth control pill taken regularly is very effective. Second, Azithromycin has no effect on the effectiveness of birth control pills, no matter what the pharmacist told you. Finally, even given the remote chance of pregnancy, the use of planb on top of all this probably reduced your chances to near zero. Expect some irregular bleeding though!