I am not a twin, but always wished I was when I was young too. My step sisters are triplets. They were actually quads, but the only boy died when he was a few days old, of an aneurism.

And no, my step mother didn't take fertility drugs. They were just freaks of nature.
There was some funny stuff about living with them when I was a teenager, and they told me lots of funny stories about when they were younger before I knew them. Like...one is good at math and another is good at English, so they used to switch classes on test days.

One NOT so funny thing was when the abusive ex-boyfriend of one (who wasn't living at home at the time) showed up at the door drunk, pounding on the door, screaming and yelling and demanding to see her, insisting that he had been watching the house all day (nice...scary stalker) and knew she was there. The guy was huge, too. It was pretty scary. He wouldn't even believe my other sister when she came down to prove that it was her who was there and not the other one.
*edited to add; OH, I did quote the other poster for a reason. Haha... Yeah, one of my triplet sisters was pretty evil, and the other two weren't. Maybe it is normal. At least, I thought she was evil when I was a teenager.