Kiirani: Looking good! It looks like a piercing gun was used. Needles sound scarier, but they actually work a lot better in the end. If you're ever going to be wanting more, avoid teh gunz 
It wasn't a gun per se.. The studs came on a little plastic thing.. I think it works similarly to piercing guns, but not quite.. I was in the middle of asking for a minute to think about whether I should request proper needles, but she'd already popped the damn things in my ears :/
She said they only use that method for ears, other piercings are done with needles, so if I intend to get any more, that's what will be used :p
As for sterilisation, as these have only touched my ears, I'm pretty sure they're sterile.