I have Checked the calender, says my period was due on september 10th, which I'm sure it came 2day early or even 3. and 4weeks after the 10th is the 8th, but I was getting my periods every 3 weeks for the past couple months, which means I was due my periods on the round about the 1st my periods havnt came yet. And it is the 6th. Does this mean I've missed a period or my periods late or are my periods. Going back to. Every 4 weeks?