Birth control implant

Hey guys I never post on here but I’m having a few concerns about my BC nexplanon. It’s the implant that goes in your arm. I used to have completely regular periods each month, but with nexplanon they have been very sporadic. Some time before Christmas I had a 16 day period and now I’m 31 days late for my next period. Any advice on how to regulate my period while using nexplanon?