Hello. I ve been taking muscle relaxers for my bad back. And I usually have sex with a condom. However, once I had sex without one, I stopped and removed myself within minutes. He may have preejaculated (or oozed) but we did NOT finish. I ve taken several pregnancy tests, all negative yet my period is late. I need to put my mind to ease. Please let me know if you have a reasonable explanation. Iv taken 5 tests (all negative), 2 on the 19th, 2 on the 25th, and one yesterday the 27th.