Basic timeline of my symptoms:

Friday - departed from Iowa (1150 ft above sea level) and arrived in Denver, CO 12 hours later (5000 ft).
Saturday - departed Denver and arrived in Breckenridge (9600 ft). Unable to sleep more than an hour at a time overnight.
Sunday - normal day, lounged around lodge and took walk around town. Still unable to sleep at night.
Monday - normal morning, afternoon began experiencing abdominal discomfort in lower right quadrant. Not constant, not painful, just pressure and occasional "twinges" of discomfort. Unable to sleep at night.
Tuesday/Wednesday - same as Monday plus began feeling flushed in early evening each day, which resolved by taking a walk in the cooler air outside. Still unable to sleep. Didn't eat any solid food other than yogurt, though definitely had an appetite.
Thursday - left for home. Arrived after long day of driving/riding and got great night's sleep (only 1 hour of sleeplessness all night). Again, ate no solid food, but got calories from fruit juice.
Friday - developed headache, but flushed feeling was gone and abdominal discomfort seemed to lessen some, though still present and with occasional "twinges" in lower right abdomen, some in pelvis and flank. Had a bowl of soup and small helping of mac-n-cheese.
Saturday - took care of headache with one Advil. Abdominal symptoms seem to be evolving or lessening (can't tell which) into pressure rather than discomfort and twinges...sometimes a feeling of fullness or pulling sensation. Subway for lunch, tbd for dinner.

So...what could this be? It certainly has not gotten worse...could it truly be due to altitude and I should give it another couple of days? I initially thought appendicitis, but without any pain and without progression of symptoms in any way, I wonder how much of a chance there is of that by now after 5 days?? Any ideas? I figure I should give it a week and then see the doctor if nothing changes (for the better or worse) in the meantime. Any chance that altitude "sickness" can cause these types of symptoms??