Upset!!!

So, I have had the nexplanon implant since May 6th. I was on my period when I got it done and then got off within a week. I didn't have a period in June, but had one the last week in July and 8 days later, I'm on my freaking period again! And it's not a nice one. I am so pissed because this one kills. I can't eat, sleep, or anything really I'm in so much pain :( anyone else with nexplanon have this happen? I mean I know you're supposed to have weird period stuff happen with any type of birth control but this is just awful.