On October 9th & 10th, my boyfriend & I had protected sex. There were no tears in the condoms, but the last time, the condom fell off as he "pulled out". I was due to have my period this week, but I haven't had any symptoms of my cycle starting up. I started my first job over a month ago, a factory job, and I think it may be stress related which is why I haven't started yet, but I can't be for certain. I took a pregnancy test on the 16th & it came back negative.. Any advice?