Did I ovulate on CD 17 or 18? Please help!

Christine • Fri, Aug 14

Glow says the 17, my OPKs were negative on CD18, but according to my BBT, it looks like the 17th?

This is my first month temping and happy to see everything looks normal, at least. Unfortunately my luteal phase only lasts until 11DPO with spotting on 9&10DPO :( so I want to make sure I know exactly how many DPO I am.