Boo! for me at 19 DPO and no AF yet....maybe I ovulated later than I thought????
I know it is a lot of work, but I highly recommend charting to confirm ovulation. Then you can see when you ovulated, and it gets addicting watching temps go up (I say this despite the fact that I have forgotten to temp the past few days ). Then you don't have to wonder about af's due date, you will learn more about the patterns your body has each cycle, and know for sure how long your LP is, generally.
FX'd for you!