I can't believe you said that to her while she's on her period. *sighs and shakes head* Man, you really ARE a man, aren't ya?
Anyway, I know when I'm on my period, things that don't usually bother me piss the hell outta me, and then I look back on it, and wonder why I made such an ass out of myself by reacting the way I did.
DO NOT-- I repeat-- DO NOT BUY HER ICE CREAM!!!! If she is still on her period when you see her, and if she took anything you said to heart, she will be self-conscious and insecure. You DO NOT want to add to that by buying her a tub of ice cream, do you? THAT would result in MY bf sleeping on the couch, I think. Eating a pint of ice cream is something girls do together, not something a boyfriend should try doing with his girl when she's upset. Nonononononononono.
Same thing about the generalizations, though. They're never safe, and I agree with what was said earlier. Don't even joke about it on the phone. It's harder to read people that way, and it's easier to piss someone (especially a girl on her PERIOD-- why don't guys call it that more often lol) over the phone than it is in person, and it's typically on accident.
Anyway, I'm starting to digress, so I'll stop now. Good luck with your girl, man!