I am 26 years old and I've never been pregnant. My period is always on time, I mark the dates on my calendar so I can keep track of when I am supposed to start. Because my boyfriend and I haven't been using any form of birth control, he just pulls out. My period was supposed to start on July 9 but it didn't start until Monday July 16, late that night. At first I was relieved, but the bleeding was bright red and not very much. On Wednesday I stopped bleeding altogether. Now today, Thursday, I have had some dark brown blood. I've had cramps, swollen breasts and been extremely tired for over about a week now. I have taken three pregnancy tests and they have all been negative. Does anybody have any idea what's going on with my body? I'm so confused and would like to know if I'm pregnant or not.