High grade severe dyskaryosis - questions

I have received my smear test results (after nearly 8 weeks!) to discover that I have high grade severe dyskaryosis. I have two questions: is it normal to go from low grade cin1 to this in a year? Does cervical cancer ever get diagnosed from a smear test or is it always after colposcopy / biopsy? 

Thanks in advance.

Every woman is so different with how fast these changes occur. The Pap smear is just a screening test, not a diagnostic test. So it cannot tell for certain if you have cervical cancer which is why a biopsy during the colposcopy is done.

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First Pap smear (at 20)- high grade changes

Colposcopy biopsy Nov 2016- CIN3 and some CIN1/2.

LLETZ Jan 2017- showed only CIN3.