Dear Angie,
The following is an actual quote from a pregnancy book I received as a gift when I was pregnant with Noah. (Note that this was approximately ten years ago, not twenty as you may suspect.)
A pregnant woman's best friend can be her husband's closet. It's all there for the taking...oversized T-shirts and regular shirts that look great over pants or under jumpers (try belting them under the belly for an interesting silhouette), sweatpants that will accommodate more incjes than yours will, running shorts that will keep up with your waistline for at least a couple more months, belts with the few extra notches you need.
Take it in. Take all that amazing fashion advice in. When your husband is seven inches taller than you are, like mine is, this is incredibly bad advice. If your husband is closer to your size, chances are you will outgrow his clothing sooner or later and go flying into a depression. And even if the clothes fit, in general terms, clothing cut for a man will not, under any circumstances, fit the curves of a pregnant woman. Great advice, What to Expect book.
While I never resorted to wearing men's clothing, I did make a huge fashion mistake. I wore something very similar to this number (but stonewashed for extra specialness).

Yes, those are maternity overalls. If you don't already look bloated, these will get you to that place in no time. And the worst part: I think I dropped about forty bucks on those puppies. Hideous.
Somewhere along the line, I figured out that being pregnant wasn't an excuse to give up. I had a few things I really liked to wear by my last pregnancy. Like this blue shirt. (Old Navy maternity clothes have such a nice fit.)

But my favorite clothes ended up being ones that weren't even in the maternity section. There are loads of shirts that are very forgiving of a budding belly. Plus you don't feel totally ridiculous wearing them when you are just starting to show, and you don't feel terrible wearing them for a couple weeks after the baby. My favorite non-maternity preggo fashion? The dress I wore to your wedding. (Yep, I was six months pregnant here.)

I am no fashion queen, but it seems to me that today's maternity fashions are really heading in the right direction. If you are active and eating healthy, there are parts of your body that will continue to look good. Why not show off those slender arms or shoulders? If you have nice legs, give them their due glory. I know that some people don't like the tight shirt look, but I think it is great to embrace the belly a bit, especially when it is as cute as yours!
And finally, don't feel guilty about spending money on clothes you will only wear a few months. Who cares? You deserve to feel good and look good! Just be sure to save a bit in the budget for when you hit about 34 weeks. A new outfit or even just a shirt can go a long ways when all you can think about is meeting your baby.
Love, Julie