Pink spotting

Lindsey

Has anyone ever had pink spotting 9 days post ovulation but then a negative pregnancy test? I thought it could be implantation bleeding cause I had that with my first pregnancy. I did test 1 day before AF is due but my bbt temps seem to be going down as well so I’m figuring im out. Why else would I spot like that? Anyone have some insight? I also had lower back pain which I never have so it’s just weird. Thanks!