I got my Nexplanon implant February of 2016. I immediately wasn't having any periods or any symptoms up until around December of 2016. Since then, I've been having light-moderate brown/black bleeding. Sometimes there's an odor but most of the time there isn't. I'm having pelvic pain from time to time. This is happening for the most part regularly once a month. Is this normal? It's starting to freak me out a little bit.