hi, i missed my depo shot about 4 months ago,i was late about two weeks, i had to reschedule my appointment for my shot ,my doc had me take pregnancy test , it came back negative then they told me to come back in about two weeks to get another pregnancy test, during that time me and my boyfriend were having unprotected sex and when i whent for my appointment i had another test come back negative, they gave me my shot, could it have been to early to detect? i been feeling sick, nausea , head aches all the things that would make me believe im pregnant could i be?