Hello, everyone. My boyfriend and I have always used condoms. However, on the 3rd of this month, we had unprotected sex, twice. Now, I'm not sure if urinating before sex is effective in preventing pre-cum, as I've read mixed reviews and information online. But both times before we had sex, my boyfriend urinated, (twice within one hour). He is confident that he didn't finish inside me at all during the first time, and 95% confident that he didn't finish inside of me the second time. He said that the second time we had sex, he felt his penis pulsate and immediately pulled out, but then he ejaculated about 4 seconds after pulling out. On the 5th (about 33 hours after that night), my boyfriend and I went to the drugstore and bought the Plan B pill. Earlier during the day that we had unprotected sex, I was bleeding a little bit of dark brown blood. The night after I took the Plan B pill, I started noticing that I wasn't bleeding a little bit of dark blood anymore. My periods usually don't carry distinctive patterns, but I would say that I'm a little over a week late. It has been exactly two weeks since the incident. I took a First Response pregnancy test earlier today and the results were negative. Should I be worried still?