help!!!!!

• i started having these lower right abdominal pains, almost like throbbing, a few days ago. i've been having lower pack pain and slight cramps. i've been spotting as well but that's because i'm currently on the arm implant bc (nexplanon) i would normally think i'm pregnant, but i'm on nexplanon.... i don't believe i could be part of the .02%... someone pls help me with what this could possibly be?