I was on the depo shot twice last year and i was supposed to go get it on november last year but i decided not to. On December and January i got a very heavy period for 2 weeks straight ea month. On March and April i got my normal 7day period. May it was very light that i didnt even have to wear anything to prevent spotting. And this month i was supposed to get it 6 days ago and ive already taken 2 pregnancy tests both negative. The first one i took it wen i was 2 days late and the other i took it yesterday. These past days ive had headaches, cramping, very rare nausea here and there but i have had lots of heartburn. 

Has anyone had any similar symptoms before?