 [ Symptoms ] is it possible to start your period a week early  i have been keeping up with ovualtion and i was ovulating saturday march 10 i had sex friday9 and on sunday11 started cramping during the week and was throwing up and nasuea on thursday14 and friday15 and now on the 17 of march i am bleeding and it doesnt feel like a normal period im crampin more and its light one minute and heavy the next [ Disease ] yes it is possible and not uncommon if you keep doing this month after month or several times in a year you need to see a gynecologist about it you may need to have your periods regulated often done with birth control pills