light pink spotting 4 days before AF

Natasha • I`m 25 years old, I had excision surgery for stage 4 endometriosis in October 2016. Endo already growing back due to trying for baby. Husband has testicular failure. Looking for positivity 💞
Hi ladies
I've never had spotting before AF is due before and I'm due Friday. When I went to the bathroom I had very light pink discharge on the tissue. I'm wondering if this is implantation bleeding? I have had cramping on and off for the passed few days.