At this point, I can still squeeze into some of the larger exercise sweatpants and shirts that I purchased after finding out about my pregnancy. But in a very short period of time--probably just another few weeks--I'm going to have trouble fitting into my workout clothing. As a result, I've been doing some browsing for maternity exercise clothes.
The results? In the secondhand market (eBay, thrift stores, etc.), there's almost no maternity exercise clothing. The same is true of discount stores (like Wal-Mart). There are some very pricey specialty stores that sell maternity workout gear, but the cost is crazy! A 3-piece yoga suit like this one costs $118! That's way ridiculous!
Since I'm not running or doing anything super strenuous, I don't really need fancy moisture wicking fabrics. I'll probably be ok in just plain cotton tees and shorts this summer. It's not the best choice, but it's certainly the most economical.