First time paying quarterly taxes and well they are due tomorrow I had no idea I had to apply for a PIN through eftps.gov so I did that now they are late.. What do I do?

I had no idea I had to apply for an eftps PIN.. eek.. Now that I did that they wont mail it for 7 days and my taxes will be considered late.. any idea what I can do? this is the first time I have done this....