When does implantation bleeding usually occur?

My ovulation cycle was last week. We had intercourse almost everyday BC were TTC. Well it's been a couple days since we have done it and just today we did and I went to the restroom after to rinse and clean myself off and I seen light pink blood when I wiped and in the toilet. Could that possibly mean implantation bleeding?I also noticed I felt faint pain in my lower stomach like I was being pinched in my uterus lol what could this mean? Im 8 days away from my AF