I need advice ASAP

I have had nexplanon for a little over a month, and at times my arm will ache either near the implant or on another area on my arm. Do you think that this is ok? I recently had sex and the condom broke and I'm a bit scared... cause I'm scared that if my arm hurts what if the implant isn't working? I just really need advice or someone to tell me about it I go to the doc Friday to have a check up that I requested but I am a bit scared, is this okay.?