Give it another few days, periods are not always on time. No worries yet. See what happens. I think you are just a bit late. Sometimes worrying about it can also delay it. Relax and see if it arrives.
Missing a period when you're on birth control doesn't happen for the same reasons as when you're not. Often women on the pill miss periods for no reason. I missed a few here and there when I used to be on the pill but I knew there was that side effect so I didn't worry about it.