Spotting after starting birth control

Cece
I got the birth control arm implant on March 1st and it's almost been 3 months since I started it. For the past 2 months maybe I've been nonstop spotting (and I normally never spot) and the spottings been brown and icky looking. I've been trying to wait it out because I know periods usually just go away around the 6 month mark but it's almost summer and of rather not be worrying about tampons while I'm swimming or whatever. Just wanna know if there's a way to stop the spotting or if I have to deal with it for a little while longer, thanks!