I am always on time and regular with my period never late never shorter then 4 days.
In august i was sexually active on my "fertile" as i keep track on my period tracker app that has always been right with my times of expected period.
In september my period was 3 days late. I took a test and came back nagitive. This month (october) i was 1 day late and only had my period 2 days... And ideas?