Today is my expected period day I.e 27 day , as it's my usual cycle length. I'm feeling dizzy and my heart beats at 120 if I move little , this is happening past 4 days . But from night I'm having backache which I experience before or during period . I don't know how all of sudden I'm experiencing this , so this month also no chance ? I wann test today but doctor mentioned to test after missed period , so waiting . Feels like pregnant with rapid heart beat and dizziness why all of sudden pms kind of symptoms started ? Is it mean period is on the way ? Is some sort of chemical pregnancy happened ? What can be done to avoid this next time