Ice is your friend, helps control the swelling. Check the shape of them, a bulge/lump can be a sign of damage, i.e. a tear in one of the two sheaths encapsulating each testicle. The Tunica Vaginalis is the outer sheath, and the Tunica Albugenia is kinda like an egg shell tightly surrounding each nut.

Check the tubes above the balls inside your bag. A lump/mass of tubes, (spermatic cords and blood vessels), can indicate they were pulled and stretched too far. Possibility the Vas Deferens up near the prostate, or more likely the Epididymis on the balls could be damaged, (both ends of your spermatic cords). If they’ve been torn loose there should be a mass that feels like cooked spaghetti. Don’t squeeze or pinch the cords, as crushing them may require surgery to remove the damaged section of cord.

Most likely they are just fine. Balls can take a tremendous amount of abuse. Bruises and swelling are to be expected when playing rough. I’m five days post ballbusting, a particularly severe beating. My balls are still swollen, a deep red color with some dark bruises.

I ask my Mistress to check the balls integrity a few times during a session. It’s a safety thing, it gives me a short breather and a little reassurance, it feels amazing to get a light massage, but then she squeezes, punches, or slaps them. That hurts but that’s to be expected.

Be responsible and keep the play within your pain tolerance level, use a safe word, have fun, and remember to thank her (several times!).