Is this possible ?!

Crys

I haven't had sex since Aug 1 I had a cycle in August and my cycle for September was only 2 days the 2nd day was spotting. I've been tired for a while and had serious back pain and my gums been bleeding while brushing. I went to the dentist and nothing is wrong with my teeth or gums. I also took a test and it was negative. I can't be pregnant... right? Is my mind playing tricks?