Well I had sex July 1st the same day my period started and 2 to 3 weeks later I started to feel like I was going to vomit then I started to feel light headed and having light headaches by the 21 I started having little cramping and very extreme tender breast and I've also notice my nipples and areola got darker so on the 27 and 28 the cramping got worse and my period come on again on the July 29  light for 2 heavy for 2 now I'm bloated and always on the toilet and slight peilvic pressure but on July 28 I took a test and it was negative...... I've went on baby center and calculated my due date and I would be 6 weeks if im pregnant still having extra saliva and food cravings and pelvic pressure ?????