Hello, I ve been experiencing a lot of pregnancy symptoms including, missed period, brown spotting a week and a half before missed period, twinges, cramps, bloating, gas, fatigue, some lower back pain, hot flashes, but not nausea or sore breats.. I took 5 tests which all came back negative. I took 2 before missed period and 3 after and all negative. If I m not pregnant, what else could this be as to why I m experiencing these symptoms ?