Just need some reassurance

Ladies- today I am 9 DPO with AF to start on Sunday. 3 days ago I began having af- like cramping. Yesterday the cramping was pretty terrible ( it's noticeable and uncomfortable, but better than af cramps) and I started getting brown discharge that I continue to have today. Does this sound like implantation? It feels like the start of my af...I took a test this morning and it was negative. ( I know it's super early to test...I just had a momentary lapse of judgement)

Does anyone have any input?

Thanks <3