You need to talk to a medical doctor about this. If its the same doctor from two years ago, he can check the accuracy of the first test--or give you his opinion of it's accuracy at that time. ( ask him what are the statistics of false negatives..) He can also redo the second test. I cannot give you a medical opinion, but I do know that you can have false negatives and false positives in most tests and it might be worth having the test again. It could have been wrong either time.
More importantly, you might want to share these test results with your husband. If you have no reason to believe he has been unfaithful to you, you might just puzzle it through with him. If you think that there might be an issue on the table, then talk to him and tell him your fears and see what he says. Don't accuse him of anything- just talk and see if there is something that needs to be said, or be reassured, etc.
HPV can be carried from skin contact, not just intercourse. It is possible to get it from oral -genital sex or even just petting, possibly kissing. It is very common and more than two thirds of people who have been sexually active are believed to show exposure to HPV.
If your husband was sexually active before he met you it is possible you could have gotten it from him. Ask your doctor if it could have been undetected by the test for any reason the first time.
In any case, my part of this issue is , no matter what the tests show, to encourage you to talk to your husband about your feeliings and fears.
I was told by my doc that HPV can lay dormant for up to five years. HTH.