nemeseri, guessing from your posting location, you are on the central Calif coast. If that is the case, you could get over to Yosemite and climb Mt. Dana the weekend before you go to Mt Whitney. It starts the climb at almost 10,000', and goes to 13,000' so you would at least get some exposure to high altitude. While you would not be that high for as long as Mt Whitney, you would at least expose yourself to a similar elevation.
You could head over Tioga Pass the night before and sleep in or by your car (there's a secluded turnout across from Ellery Lake, 1/4 mile from the Saddlebag Lk road.)
Even if you hike Mt Dana, Mt Whitney is a bigger beast. You will be higher for longer, so that gives the altitude longer to act on your system. You could be lucky like some, and not feel any effects. You won't know until you go and try.
I think you should go for it, and get up as far as possible. Just remember, the mountain isn't going anywhere. If you don't go all the way, the trip will be well worth the learning experience. Then next time, you will better know what to expect.
