I'd say so. I just loaded up on a bunch at the outlet in Vegas and normally wear size 6-8 depending on the brand, and most of the size small fits me fine. They carry some different jean brands though, and sometimes I'm a medium in those, but that's normal for jeans to fit weird like they do when we're not pregnant! Don't even escape that when looking for mat clothes!
If you've ever been pregnant, you know that maternity jeans can be a real saviour for your wardrobe. As your waistline expands, everything starts to not fit quite so well (sob!), and it can get uncomfortable—not to mention expensive. But if you have some decent denim options at your disposal, you can at least wear some of your looser tops over your bump. And there are some brilliant jeans that can help with that.