Just had my third boy a little over a month ago, and, um, yes, everything you said. My MIL now has 6 grandsons and if I had to guess, would have been happy with 6 granddaughters (and no grandsons). I was so stressed out about disappointing her and getting stupid comments that I went through this whole song and dance that we had to announce it on our family blog, and the wording had to be just so (had to convey that we were happy and deter comments), and then my DH told her on the phone and I was upset because I thought that made it into a big thing ... turns out she had already decided it was a boy to protect herself from being devastated ... ugh.
I have to say, though, that the worst comments came from strangers at the store who saw me with my two boys and their eyes would light up and they'd say, "a girl this time?" and I would smile back and say "no", and I'd have to watch their faces fall and then fumble for words. One clerk at Costco actually said, "you wanted a girl this time" and I shook my head and she looked confused and said "you wanted another boy?" like I had said I wanted to give birth to Hitler. I said, "we would have been happy either way" and left it at that. Another time, the photographer at Picture People said, "oh, you must be so disappointed, I bet you wanted a girl this time." I took it pretty well but it bothered me for days.
At least everyone in both our families, as well as close friends, are clear that we were not "trying for a girl" because I always told people I wanted 4 kids before I ever got pregnant. It still bugs the crap out of me that strangers assume it, though. I'm sure when I have our 4th boy in a few years, if I am blessed with a 4th pregnancy, that it will get even worse. Pooh on them -- they have no idea how wonderful our sons are! The only appropriate response when someone tells you the sex of their baby is "congratulations" -- period.