Bad sex or just me?

Hey ladies, I’ve been having this problem where whenever me and my boyfriend have sex recently it feels like nothing - as if I just lost all the nerves down there. The only way I can feel anything anymore is if he goes down on me but when we are actually having sex I basically don’t feel anything. We’ve been dating for over a year and this has never happened before, it’s always been really great sex. I’m on the implant (nexplanon) but I’ve had it in since January and this problem has only started happening the last couple weeks. Could it be just me? Should I see my doctor? Please comment I would really appreciate it 😭