Unseen cells

Hi, im new here but was a little unsure on something after my colposcopy today after my smear had shown mild cell changes, i’ve had HPV for 5-6 years now. All my previous smears had shown borderline changes but this was the first that had turned to mild abnormal cells. The past 3 months I’ve started bleeding between periods.
So had my colposcopy today and they had said they couldn’t even see the cells to take a biopsy as the cervix was too tight, i asked if that was a good thing but seemed to answer with “if i can’t see them, i don’t know whats going on”. Has anyone heard of this or had this result as I’m still left without a definite positive answer, thank you.