I've never had anyone comment on breastfeeding in public- except once when I was trying to use a blanket to cover up and my DD was squalling because she hated it, and some older woman stopped and said, "Oh, she just wants to see what's going on! I don't know how you can see what you're doing, it always takes me about a year to figure it out so I can do it without looking!" (basically telling me to ditch the cover up- which I did). I definitely got a lot of weird looks, but I think people just look at you weird when you've got a baby, regardless of feeding methods, so whatever.
Casmer- I don't use my diva cup at all for the first day or two of my cycle, it makes my cramps worse. I usually only get them for the first day or two and usually fairly mild, but the diva makes them hurt a lot more.