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: