Implantation bleeding? any advice is very appreciated.

So ladies, I got off my period a week ago. It's now day 6 and I went to the toilet, I wiped and on the paper their was a light pink colour mixed with my discharge. Not alot, just when I wiped. I've been sexually active with my partner but I take the pill (Don't take it at the same time as I should) I understand there is such thing as breakthrough period but I've been on the pill for 7 years in total and not once had this happened. I'm getting very faint pain in my lower stomach. Is anyone thinking pregnancy or am I over thinking? Any help would be great! Also my mum got pregnant on the pill and she was also spotting. Do I continue to take the pill or not?