I agree with Emma. As long as your paps are fine, I don't see the point in knowing. It's probably cleared by now anyway.
I also saw an advertisement for the HPV test. Personally, I don't think you need to get it. You have had all normal paps and you have been with the same person for 18 years. Assuming you and your partner have just been with each other for the past 18 years, if you had HPV (even high-risk), it has probably cleared. I think the test could be good in conjunction with the pap test in some circumstances...but I think for you, yearly pap tests are enough. But then again, I'm not a professional...your doc's advice is better than mine :)
Best wishes,
Em