Understanding Abnormal Pap Smears & HPV: A Comprehensive Guide

Question
Hello, I'm hoping you can help me as I really need some advice and couldn't find anyone else to ask on this site. I hope you might have some experience with my situation and apologize for the length. To start, I had my first abnormal pap smear around april 2009, and had a followup with a colposcopy around that time. During that, they took a biopsy of an area of the cervix which to them resembled cell changes related to possible HPV. Upon further investigation during biopsy, they concluded squamous cell changes of undetermined significance and a negative HPV. They followed up one more time with another colposcopy couple months later which showed normal cervix and no cell change. I then went to a specialist office who did a repeat pap march of 2010 (about a year later almost)and was normal. Now in november 2010 during a prental appointment (found out I was expecting in august 2010), I had a high grade abnormal pap. Colposcopy concluded it was actually low grade, and then another pap couple weeks ago now march 2011 I am positive for HPV.

Question is, how can a year or more later after the last normal pap in march 2010 and all the normal colposcopies prior in 2009, does HPV now show up almost 2 yrs later?

I am married and this is causing some stress in my marriage as I feel after a negative hpv in 2009, this might be a new strain? Or possible was lying dormant this entire time and 2 yrs later showing up ? (During that time 2 yrs ago before april 2009 my now husband and I werent married and we were not together at that time but had dated other people for a short while). With my first pregnancy in 2006-2007 there were NO abnormal pap problems and no hpv testing. But this time there is a positive?

any advice, or maybe helpful sites you can find about my specific situation, a normal and then positive hpv or know anyone to ask?

Thank you so much for your time and any advice is greatly appreciated!!

Answer
This is always a tough subject because so many people are infected with HPV and don't show symptoms and there can be spontaneous regression and occ recurrence.  Plus, the pap smear is not that sensitive, in that it may miss HPV pretty easily.... if it were perfect, we could get by with pap smears every 3-5 years since it is such a slow process.  The other issue is your husband may be infected and re-infecting you.  It is really really common, 50% of sexually active college females have it.  

So there is no evidence that someone has been cheating.... it can lay dormant.