Tell everyone that you are getting your first shot on a Friday, call in to work on Monday with “not feeling well” come back to work Tuesday complaint about a fever and soreness but no big deal. Repeat two weeks later. Unless they require you to show the card this should work. Other wise, make a card and laminate it to cover the thickness and you are on record with the company of having been sick twice after taking the shot. Edit to add; you got the shot at Walmart and they are famous for losing track of people who took the shot