Plan B affect your period???

So a couple weeks ago I had a sinus infection. I was put on antibiotics for 10 days. During that time, I had sex twice. One was unprotected, so I took Plan B. When the pharmacist gave me the antibiotics, she said to use a back up method of BC. After we had sex, I did a lot of research & found that there is no evidence that the antibiotic I was taking decreases your BC's effectiveness (only one to treat tb). But, I took the plan B just in case. 

I am on the pill and have been taking it religiously, so I took the plan b with it. I'm supposed to get my period tomorrow, as tonight is my 3rd placebo pill I'll be taking. I was just wondering if the plan b could make my period come later or if I should be worried at all???