I swallowed my temporary crown. How much shifting may occur in three days?

Everyone is different. Some patients can go weeks without a temporary crown with no shifting. Some patient loose a temporary over a weekend and the teeth shift considerably. Definitely get a new temp as soon as you can. But a few days shouldn't create too much of an issue.

Hi:Missing the temporary for 1-2 days should not create any significant shift for your final crown.  Keep the area clean.Best,Dr. Maddahi

It usually takes more days than 3 to have a considerable amount of shifting, so it could need reprep. 

I recommend you to see your dentist or somebody from the staff Monday.