Its my first time being on the Depo shot i did wait the seven days i was suppose to on the third week of being on the shot i had unprotected sex he did not ejaculate in me but i still have not had my period i only spotted for about six days after the intercourse, now i have been having back cramps and i feel bloated sometimes like if my period was coming but no period at all could there be a possibility i could be pregnant?