I, too am going to disagree with some of the pp's.
First of all - it is the height of rudeness to bring uninvited children OR to call and 'ask' if they were inadvertantly left off the invitation. That puts the bride and groom in a horrible position, and if they WERE invited, it would have indicated as such on the invitation..
Well, now...sometimes the people inviting forget to mention things...my oldest friend and I got engaged at the same time, and originally had our weddings one month apart. My then fiance and I had some problems and had to postpone. When I got the invite for my friend's wedding, it was just for me...I asked my fellow b'maids, but none of them had "and guest" on their invites, and none of them were married, engaged, or even boyfriended at the time, so I was at a loss. I finally just asked the bride, and she said that of course he was invited, she just wasn't sure how to invite him (she wasn't "and guest"ing but was inviting significant others by name, but didn't know his last name or his address). If I hadn't asked, I would have been a lonely chica at the wedding, and she would have been very confused as to why he didn't come!
So there ARE exceptions.
However, in this case, where the "no kids" rules was stated before the OP found out there were at least a couple kids invited, there's no confusion there. For whatever reason, they invited those kids and none other.
If I were in your shoes, I might take DH and DDs to the area, make a weekend of it (even if it's only an hour away), you cut out for a few hours while DH and DDs have a nice little time (swimming, out to dinner, other daddy/daughters bonding things?) and you go to the wedding, then you come back and regale them with stories, and go on with your weekend.

Maybe even rent a suite so your sons can come back and stay over, depending on how old they are and what they are actually up to at the wedding, of course.
