Can someone tell me how long there implantation lasted? And severity? And what day in cycle

I took a test yesterday and i was 9dpo and there was a very faint line it was clear blue and people say they can be bad for faint positive then that night I started to cramp and it’s continued into today it’s in my lower back and lower tummy and feels like period cramps almost maybe not a severe but deffo there more annoying than anything .. I am due my periods in 5 days now I think I’m not pregnant and af is on the way due to the intensity of cramps :(

Implantation or Early Period?