The "test of cure" process- advice please!

Hi there, I am feeling quite confused about the test of cure process after CIN3 found and LLETZ done on September 2017 - confirmed CIN3 with unclear margins (first smear at 24).

I went for my test of cure smear at my local GP last Thursday and awaiting results, but I was shocked to hear that if my body has managed to fight the HPV virus, then they won't look at my cells (pilot study area). This really worries me as the damage has already been done in my cells, and following treatment I was told I had unclear margins and would probably need more LLETZ. The nurse was also surprised at this and didn't seem to know the process. Why would they not check the cells in mine and many other cases after potentially missing CIN3? Hoping someone can give some insight or experiences.