Interesting thread, ladies.
I think I'd feel weird if a woman ever proposed to me. Not that it couldn't happen, but I think I'm too much of a traditionalist to let it go down that way.
As to "pressure" I think I agree with Summerchild, but subtlety is key. I think if it's a good relationship you know after a reasonable amount of time (I define "time" not by a calendar but by the level of spiritual commitment and range/depth of experiences you've shared together) whether she's the one you want to walk into the future with.
If I had to get "nudged" at all, I'd rather it be gentle rather, than overt. It still has to feel like it's my call on that level. ...because it is.