Question: My probationary period passed three days ago, I have not been told if I passed it, and I have my evaluation early next week. Should I assume that I have passed probation?

Answer: 
No you should not assume that you have passed probation. You will likely be informed of the results of your probationary period during your evaluation.
Never make any assumptions. Talk to your manager, mention that the period ended, and ask if you need to fill out any paperwork, or if there is an official review involved.