Timing doesn't sway. If you're asking me if that is supposedly Shettles timing for boy, yeah technically (they would say CD 17 would be "bluer"), but it is also IDENTICAL to the point at which I BD before O and got my daughter after getting 3 of 4 boys with cutoffs. :) I can assure you with every fiber of my being that it is entirely possible to get a girl that day. :)
Yes, it's possible to O days after a positive OPK.