Act immediately. As soon as you are back at university, go and see your instructor. Explain the situation clearly and indicate that you can supply documentation to support your reason for missing the test.
Check to see if there is a particular form you need to fill-in. Some universities require this form to process your application to make-up coursework. In other cases, you may be able to negotiate directly with the instructor.
Provide verification. Just saying you were sick isn't good enough. You will be required to get a letter from a doctor saying you were ill and unable to attend classes. In the case of a funeral, a note from the minister or funeral director should be sufficient.
Meet with the instructor and agree to a time and date to make-up the missed work. Once you have done the necessary paperwork, arrange to make-up the work as soon as possible, to avoid falling further behind.