Here's how I do it -
Pup is either tethered to me
Within eyesight (and my eyes are on her) or
Crated when indoors.
If I play with the pup, it goes outdoors NOW!
If I feed the pup, it goes outdoors NOW!
If the pup drinks, it goes outdoors NOW!
Any exception & I am screwing up
Any accident is my fault not the pups
At twelve weeks they can be 5 to 5.5 hours or so without having to urinate.
Be vigilant, be active, be aware.
I only used puppy pads in the dog carrier that she rode in under the seat in front of me on the flight home. She used it once, I changed it in DFW as I boarded the shuttle bus. The new one was still clean when we got home.
Don't use puppy pads if you can let a 12 week out every 5 or so hours.