Nexplanon Implant?

I recently got the Nexplanon, May 2nd to be exact, and I definitely felt it. The lady supposedly numbed my arm, but I felt that thing go in, which of course hurt. It is now May 5th, I still have bruising and it hurts/feels sore. I can't lay on that side and have to watch how I place my arm when I go to sleep. I have yet to seriously bump it so I'm okay in regards to taking care of it, but when I do move the wrong way, I feel like a stabbing pain in my arm. Is that normal? Is it possible for it to slide back out if I continuously accidently keep "stabbing" it before it's fully healed? How long will it be like this? I can't sleep comfortably due to me having to sleep on my back with my arm a certain way. This is my first time getting this and after reading horrible stories of it being put in "wrong" and not working, I can't help but be slightly worried. I was told to give it two weeks but I still feel the need to ask about the stabbing pain I feel, and would like to know for those of you that have had it, how long did it take you to heal and afterwards how was it? I was supposed to start my period yesterday but haven't due to (I'm assuming) the hormones in this thing. So I guess it's working. I just have a history with my belly button piercing getting rejected/infected and worry that maybe my symptoms mean it could be happening with this thing too. I'd just like to hear people's knowledge and experiences with the implant. I did ask my doctor, but I feel it's not exactly the same as hearing actual people's experiences.