I found an interesting article today talking about what happens if you miss your second vaccine dose. It was pretty plain and simple that it's not that big of a deal to be a few days late on your second dose. The CDC says that you should obviously make it a priority to get it asap (within the bounds of when you should), but you technically can miss your second pfizer dose by a little bit. CDC says that you can get your second dose by up to 6 weeks after the first dose, for both the pfizer and moderna shots.
Just wanted to put this out there since it's not always easy meeting the specific intervals they give you.