New to Nexplanon

Hey, guys! I was put on Nexplanon (the arm implant) last month on the 3rd or 4th day of my period. My doctor told me to expect a change in my menstrual cycle, but she said typically it’s normal for three months, and a lot of girls do not have a period after that. I am currently 3 days late for my actually period, but I started spotting about a day before I would have gotten my period. Has anybody experienced spotting replacing their period after getting the arm implant? I just want to make sure this is normal.