anybody else going through the same??

Melissa
I got my depo shot in September 2016 and I was supposed to get the 2nd shot in December but I didn't because I started gaining too much weight so I decided not to take it , so I've been having unprotected sex with my husband but I been bleeding abnormally, 
I thought I got my period twice last month and out of nowhere I saw pink when I went to the bathroom yesterday than it turned to brown and now I'm cramping bad and only bleed when I use the bathroom, 
Im not a depo fan, it really messed me up
Any suggestions??