ok so my last period was on dec.1 i got the depo around the 31. the doc went ahead with a preg test it was neg so she gave me the shot, even tho i hadnt started yet. she told me to take another preg test in two weeks if i hadnt started yet. i didnt start so i took one it said neg. so when i went again they still thought it was weird so they did another one. it still said neg. ive been really nauseous, lots of lower back aches and head aches. i feel preg but all the tests say im not...???? any advice.? is this all from the side effects of the shot?