Nexplanon

So I have nexplanon, the implant in my arm. 
It's been hurting recently, I've spoke with my OB but she didn't give me much info and said its fine. 
(She's not the doctor who put it in) 
I've had it since last August. 
It's been great and all, no problems, but for the past two months it's been causing pain in my arm. I feel like it sticks out and pokes my skin sometimes. Or the angling has changed. Idk. Anybody else have this problem before?