Could I be pregnant? Paranoid (on pills)

I have been on birth control pills for a while now. Starting on a Sunday I started taking my pills that week at different times on accident. I still took them each day they were all just not at the same time (more than 3+ hours apart for some days). I had sex with my SO that friday and even though I'm on those pills we still used the withdrawl method. I'm just kind of scared since I took my pills at different times prior to that day there could be a chance im pregnant. But I don't know for sure. Any thoughts??? How likely do you think it would be?