I've noticed that after I put extreme, ridiculous pressure on my fingers one night, my fingers for the last week look really chunky, a lot rougher and thicker. I feel like it's the bones themselves, not retention. If, very hypothetically, you put as much pressure on them as you would in 1 year in a few days, would there be the same amount of change? I know I sound like a hypochondriac, but would it technically be possible? Would the bones go back to their original size after less use?
Bones and tendons take quite a long time to condition due to pressure. Generally the remodelling you do see see happens over a prolonged period of time. The sort you see most frequently is in athletes, power lifters and body builders. That would be remodelling that is not associated with trauma, but with conditioning.
When you investigate the bones (in an anatomy lab) of individuals who did resistance training, you can see the effect on the bones, like on the clavicle for instance, where the pectoral muscle attaches. You will see that the bones remodelled over time to accommodate the increased stress.
This type of process of bone remodelling is subject to tendon and ligament conditioning and remodelling which takes 18 - 24 months to remodel. This is one of the reasons you see athletes get repeat injuries. Once an injury has been rehabilitated, such that the pain is gone and the muscle strength restored, the ligaments and tendons aren't fully healed after only 8 weeks.
As for bone only, that happens a bit quicker than the connective tissue like tendons and ligaments.
To answer the question though.
Think about this, can you fix your broken finger in a very short period of time, by waiting? No. It takes 4-6 weeks for the bone to reattach, and that is if it remains immobilised.
I suppose, theoretically, you could remodel the bones in a similar period of time, if the exposure to the stressor was also applied consistently over the same period of time (4-6 weeks).
Though probably not thickening of the bone. Thickening of bones is primarily in response to stronger muscles that consistently add longitudinal pressure on the bones over a long period of time by virtue of being trained over a long period of time.
In the short term, what you are experiencing is probably just inflammation.