That's funny you said that, Jessica. EVERYONE has been saying that to me lately. I'm honestly not too worried about it, though. I'll be starting my 2nd trimester next week and I'm not showing one bit. I can still wear all of my pre-preg clothing comfortably. I am pretty certain that if it was combo of twins + 4th pregnancy, I'd be showing by now!
Thankfully, twins don't run in the family. There are a couple identical sets on my mom's side but those are supposedly not hereditary.
And, Katie, all of my pregnancies have been different. This is definitely the worst, but every single pregnancy, my nausea affected me a bit differently. So I wouldn't worry too much about twins!
I too am looking for workout videos for pregnancy that are actually challenging. I could just use bits and pieces from my pilates videos, but it would be nice to not have to stop and jump around continually. I suppose it's time to browse the amazon reviews, as I imagine libraries don't have a huge selection of pregnancy workout videos.