First, it is *normal* to be worried the day before your first marathon. The worries will mostly go away when you line up at the start line.

Second, many slow people who miss the cutoff go on to finish the distance. While they are not official finishers, consensus in the running community is that if you covered the distance, you ran a marathon. You don't have support after the cutoff, and roads will be open; but how different is that from training runs? Any humiliation you feel will be internally generated; other marathon runners will respect you for doing what it takes to go the distance.

While I have no personal experience with missing a cutoff, I know it felt terrible to take a DNF face down on the sidewalk a mile from the finish line because I couldn't walk another mile. That would have made me give up marathons completely, except I was already registered for the next one. The next one went much better, and I've done one more since then.

. . . but if that DNF experience had happened in my first marathon attempt, it might well have been my *only* marathon attempt.

As Moby said, you may not get a medal or official time, but usually you are allowed to finish the race if you are over the time limit. (I think Disney has sweep buses.) At Boston there were people finishing in 8 or even 12 hours. In a small race, you may find yourself with some emotional support, with people coming back to help cheer you on or at least waiting at the finish line to cheer. You won't be the only slow one. However, there probably won't be any post race goodies and there may not be water at the end, so if you are seriously concerned, then make sure to bring your own water. Just don't touch it until you actually need it.

OTOH, you may find that race day excitement will get you through much better than you expect now. Before my first marathon, I had injured my hamstring. It caused issues during my training a couple of times, so I wasn't sure how it would do with a full race. When I was running, I kept doing the math in my head: "okay, 6 miles done, 20 to go and 5 hours to do it in. Can I walk that fast?" Then it was, "12 miles done, 4 hours left, I can walk 3 miles an hour. I'm okay." Then I said to myself, "18 miles done, only 8 to go and 3 hours to do it. Piece of cake." Although I did walk some in the last 8 miles, I was able to keep running for the most part and finished in 4:21. My hamstring was never an issue on race day. My quads on the other hand . . .

@swebb1103 I'm late to the party. But wanted to say congratulations! It takes guts to commit to 26 miles!

Nice work! That is amazing you finished!! This is really inspiring!!