Unless if your AF usually comes around 9DPO, it's a really good sign in my opinion!
When I got my BFP I had cramps and unexplained diarrhea from 6-10DPO. I wasn't sick at all but had very loose and frequent stools. Got my BFP at 12DPO (DH swears he saw a faint line at 10DPO). If you search around, lots of women experience this and get BFPs, even if the stereotype is constipation!
Hope it's a good sign for you too, lots of baby dust to you!!