First round and OPK testing


I am on CD 17 and just did my first round of letrozole. I went on CD 13 for an ultrasound and my dr said everything looked great and I should peak at the end of the week. I have been testing FMU with clearblue and have been getting a flashy smiley for a week. I have been testing in the afternoon with the strips and have had some rise but not a peak. Has anyone else had this problem? I do not have pcos and will not trigger shot with this. My fertility dr told me to have sex every other day this week and I will go back Thursday for progesterone testing.