5 mg didn’t work, moving to 7.5

Kelly • 33, married, PCOS, Femara/Ovidrel led to #1 born 2019, #2 due 09/22

We conceived our daughter with 2 rounds of letrozole 5mg. This time, we did one round of 5 mg, not pregnant. I went in for my mid-cycle ultrasound today after round 2 of 5 mg of letrozole, and they tell me to restart letrozole at 7.5 mg for 5 more days. What does this mean? Why isn’t 5 mg working anymore? The nurse just said cycles vary. Did this happen to anyone else? I’m getting pretty anxious. To top it all off, I’ve been sick the last week, and I developed a neck rash, and I don’t know if it was due to the letrozole or the virus or some of the cold meds I took. Gosh I hope I didn’t develop a reaction to letrozole.