Replying to Need Advice! Missed a college exam, what to do?

Alright so it was a super nice day on Monday and I skipped my afternoon classes, not knowing that I had an exam in one of them. In the syllabus my professor says that we can only make up missed exams in extreme documented circumstances.

I have 2 ideas. Get a note from my "mom" saying that I was driving my grandma to the airport cause her sister died or some shit and my parents were working.

Or just wait a few weeks and be like "Hey I noticed my grade isnt in the computer for the exam... play dumb and try to convince her she lost my test.

Both of these can go wrong in so many ways, and this is really important as my grades are pretty fucked this semester unfortunately.

Does anybody have any advice? My class is at 2 so time is of the essence. THANK YOU