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)
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 friday(9) and on sunday(11). started cramping during the week and was throwing up and nasuea on thursday(14) and friday(15). 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