What Does Cervical Changes And Positive HPV Indicate?

Question: Approximately 2 years ago I was diagnosed with ASCUS cervical changes and positive for HPV (however negative for strains 16 and 18). Colposcopy and biopsy indicated minimal cell changes and I have been monitored with repeat Pap smears every 6 months ever since. My last 2 Pap smears after the biopsy have been normal. My most recent Pap smear came back with indication of high grade cervical dysplasia and I am now scheduled for another colposcopy and biopsy in one month. If high grade dysplasia is confirmed recommendation is likely going to be conization. I have been sexually active for 5 years with 2 previous partners. I have had no new partners or other changes in sexual history since initial diagnosis so it is highly unlikely that I have been exposed to a new HPV strain. I am a non-smoker and am not immuno-compromised. My concern is that this finding seems quite atypical. Should I be concerned that dysplasia seems to have progressed so quickly? Maybe this is more common than I think, however I am now starting to question the previous or current examinations. Would it be in my best interest to seek a second opinion to ensure the consistency of these findings?