Period talk

I need answers my last period started July 8 and ended on the 13 I believe augs 8th came and when I went to use the restroom I had wiped and I seen a lil lightest pink on the toilet paper so I was thinking I was about to start well it’s now augs 24 and there is no signs of any period and according to my calendar I’m now 15 days late what could it be ?