It's been probably 4 days since I last saw pee in one of her two
litter boxes. She still poops normally (about once every 2 days) and her
BM looks normal. So I'm guessing that either something's wrong with her,
or she is pee-ing on the rug somewhere that I still don't know about. She
is 2 years old next month. If she is pee-ing on the rug, wouldn't the
smell be obvious by now?

What other explanation can there be?

--
Hilary Duff turns 18 in this amount of time:
http://www.timeanddate.com/counters/...&month=09&year
=2005&hour=00&m

"At a dinner party, one should eat wisely but not too well, and talk well
but not too wisely." -- W. Somerset Maugham