Vasectomy & Recanalization - Is There a Way to Tell?

If my bits decide to grow back together, will I be aware of it in any meaningful way (e.g., it hurts like hell)?

Unlikely you’ll be aware.

If you’re wondering, get a semen analysis

I expect the most meaningful way is the strip turning blue. Whether or not that “hurts like hell” depends a lot on your situation.

You can check it yourself with a microscope. If you don’t have one handy, you can buy a kit made for this purpose:

Micra Home Sperm Test