What Causes Delayed Periods After Having Wisdom Teeth Removal?

Hi, my period is late (or isn't coming at this point) and I'm worried. My boyfriend and I are usually pretty careful with condoms and I am on the pill, but I had my wisdom teeth out a week and a half ago and now am one week late. I was put under and then on antibiotics following the surgery. I'm wondering if the stress of the surgery could have caused me to miss my period? Or if I should be concerned about pregnancy.