long your cycle is? I have no idea which way of counting is correct. Here are a couple examples of when I have began, started and began again the last couple months. I want to thank all of you who've helped in advance. THANK YOU!
BEGAN PERIOD: Oct. 30 and ENDED PERIOD: Nov. 5th
BEGAN PERIOD: Nov. 24 and ENDED PERIOD: Dec. 1st
BEGAN PERIOD: Dec. 18 and ENDED PERIOD: Dec. 25

BEGAN PERIOD: Jan. 12 to currently 2 days into my period
How do I count the days? Is having a period every 17-19 days normal?? I'm very confused. Thanks all in advance!