Not to belabor the issue but there is a difference between a pap test and an HPV test - they are not the same.
An HPV test, as you stated you had, looks for the virus itself. A pap test does not - a pap test looks for cell changes in the cervix that may be caused by various things, including the HPV virus. It's essentially to make sure you are safe from getting cervical cancer. A pap does not test for the actual virus itself.
Therefore you can have normal pap tests and have HPV that is not detected. If that virus becomes active (rather than dormant) then changes may be seen on the pap test.