Can Medicine affect Pregnancy Test Results?

Today my mom and I bought e.p.t pregnancy tests that tests 5 days before your missed period, I took one today and it came out negative, but I still missed my period yesterday, and I've been expecting it for some time now, I take a medicine called levacitrim for my seizures and have been prescribed antibiotics because I have bronchitis, is it possible that these medications affected the results on my pregnancy test, and if so, should I retest in two weeks as planned?