Hi Im 22 6'2 213pounds ... 4 Years Ago I

hi im 22 6'2 213pounds ... 4 years ago i had an ovary and cyst removal .... 2014 i got pregnant and had a baby Dec.2014 ... since ive been on three different birthcontrols ... the last being depo shot started n sept ended in dec because of weight gain... haven't been sexually active since oct 2015 but recently have been feeling thumps/ movements in my lower abdominal area , ive taken a pregnancy test and it was negative... any ideas on what this could be ? possible pregnancy?