I m 39, my periods have always been regular. My last one started on June 25th. Haven t had one since. Spotted on July 26th. Increased sex drive, Breast feel fuller, diarrhea after eating, tired all the time. I ve taken 3 hpt s all negative. The most recent one was yesterday. Never been pregnant before, so no idea if this is normal? How long should I wait before getting a blood test?