Implantation bleeding or AF

So I missed 4 pills this month of my birth control. I bled about two weeks during this month, the pill I’m on has a low amount of estrogen causing a lot of breakthrough bleeding. Anyway, AF is 5 days late. I took a test two days ago just to have peace of mind, and it was negative. Today I started getting very light pink bleeding. Is this just AF on her way? Is there anyway this could be implantation bleeding?