Implantation or AF early

Hi ladies,

Hubby and I have been TTC for over 3 years now we started seeking help from a fertility specialist about 7 months ago. I started experiencing mild cramping in the afternoon on 8dpo every once in a while its a sharp stabbing/pinching feeling right in the center a few inches below my belly button and when that subsides it's just a constant dull ache/ pulling sensation. This cramping is still happening tonight at 9dpo. I know not everyone feels implantation but this is such a weird sensation, I never cramp this early before AF only once I start bleeding. Af isn't for another 4-5 days. Is this possibly implantation, did anyone else experience this and get their BFP or is AF coming early. I will be testing tomorrow morning at 10dpo, I just wanted to see if anyone else experienced this?