Hi.My last period was jan.27. It stopped on feb. 3rd after my b/f and I had unprotected sex. My cycle is 28 days always regular and on time. I also have 2 children already and I m 38.I have been running a low grade fever since. We then had unprotected sex again the 8th,10th,11th,12th,13th,when on my fertile days and ovulation day and again on the 17th. I have been having back pain on and off, constipation,diarrhea,tired, leg cramps, abdominal cramps,loss of appetite,headaches,chills and still running a low grade fever. Its 4 days before period is due.I tested with a dollartree test and got negative! Why???