who is on the arm implant??

so, to make long story short I was on Depo, and when I joined the Navy I told them how long I was on it and they told me to switch birth control. So I got the arm implant and didn't have my period for a year, just light spotting. Ever since October of last year, I would have periods for 2 - 4 month, and then not have one again for a month or two. I looked up on the website, said it was normal. Is anyone else having this kind of problem? and do you recommend that I switch birth control?