Sabina....
honestly from looking at hundreds of FF charts when I am in the 2WW and obsessing..... I know get a life!
most women who are PG see their first BFP at 12 DPO. And lots of them tested too early before that and had a BFN first. I think anything earlier than that is just luck
15 DPO is really your best bet because implantation can occur at 12DPO.
I say test on 12DPO

Unless you temps jump up and stay up....then I'd be finding the closest HPT.
I test way too early because I really am addicted to the possibility of maybe seeing a second line. I am not upset when it isn't there ... I always say it's too early...maybe tomorrow. Well for some reason around 12DPO if it's still negative that's when I pretty much give up home.
LOTS of
and your chart looks great!