On February 17th I had sex, used a condom. On February 22 to 26 I had my period. This month I have been stressing I might be pregnant I over think everything. It is the 26th of march and I still have no had my period. I have cramping I have had it for the past week now and no period. I've also had constipation but I even had that before having sex. I took a home pregnancy test on march 21st and it was negative, could I be pregnant?