Well lets see, it is about my menstrual cycle. i started april 25th and ended may 1st, i shouldn't be starting again tell may 30th okay. my cycle is pretty regular always 7 days and starts up every 28 anywho i got hit in my lower back just early today on

A blow to your back: A blow to your back should not effect your period. However, if your last period started on April 25 and you have a 28 day cycle, your next period should start May 23 ( 28 days from start of one to start of the next is a 28 day cycle) and there is some normal variation from cycle to cycle so a period starting today would be normal. Hope this helps.