You say you don't have issues with vaginal dryness, but you did feel discomfort--difficult to sit comfortably, spasms of pain--for at least a week after intercourse. It does sound as though you experienced some trauma.
It's likely that though you're still experiencing your own lubrication when stimulated, you're experiencing some atrophy, too. I'd suggest that you start using a vaginal moisturizer (like Yes or Replens) or a localized estrogen to maintain moisture all of the time--not just when you're aroused.
If you and your partner aren't able to be intimate often (and I'm afraid the definition of "often" varies from woman to woman), you might think about some of the additional options I talked about in a blog post about "Staying Ready for Sex." It's easier to maintain your sexuality than to restore it!