Temping while taking progesterone...will there be a temp dip before AF?

[Lucinda15]

I'm TTC #2 after 3mc's. I'm on the Coventry plan for raised uNK's and am about to start taking progesterone on cd21. I'm temping alongside this, and was wondering if perhaps the progesterone will sustain a high temp even if I don't fall pregnant? Does anyone know? I don't want to get my hopes up if I don't see a temp dip to indicate AF on her way! I will of course be testing around that time I spose but I don't want to be fooled into thinking I'm pg! X