Late period or implantation?

My period was about five days late, and today I got this brown discharge. My flow is usually pretty normal once it starts but this one is a little different. My nexplanon expires next month so could it be just my implant running out? Sorry for the pics but I do not wish to be pregnant so I’m hoping this is just a late period. These pics are from two different times through the day but my bleeding is light with light cramps and no other symptoms.