Am i pregnant i had un protected sex ?

i was suppose to get my depo shot on the 8th of june but i did not and i had unprotected sex, when i dont get the depo shot i usually get a heavy period but i have not and i started spotting little tiny bit it started off brown than pink and it was on and off for like 3 to 4 days but it was a tiny bit like once a day it was like to little drops... i was getting bad cramps one of the days around the time i was going to sleep i started getting head aches.... i am not spotting at all any more. its now the 30th of june im going to get a test tomorow but i wanted to know if there is a possibility i am pregnant?