With the exception of a dress for my shower, I basically stayed away from the "this will work post pregnancy" mentality. And in all honestly, when I put that dress back on I feel pregnant and don't think I'll wear it again. I work in a casual office and didn't travel anywhere with a different climate, which made things easier. My babymoon to St. Thomas was cancelled due to the Zika travel advisory just breaking so I ended up returning a few things I bought for that trip (bikini tops and maxi dresses).
Here is a breakdown of the basics that I purchased. You will see a theme... tight and ruched!
I bought clothes as I needed them, with the exception of the Bellaband to hold up my jeans in the first and second trimesters. I purchased those in advance because I didn't want to be caught off guard one morning trying to button my jeans. I had both black and white.
lululemon High Times Pant (non-maternity) $98
I definitely got my money's worth out of these and the brushed inside kept me warm in the winter. I'll admit I would wear them to work and then straight to barre class. I went up one size from pre-pregnancy and wore them into my third trimester, sometimes folding over the top. (I also got the Power Y Tank in a size up for working out and to wear on the weekends... I was lucky to find one on sale.) These are non-maternity and the fit might not be for you because as you get bigger they won't go all the way over your belly.
These are very basic and just comfortable. Full disclosure... they don't do anything for your thighs and behind like lulu will. For me they went all the way over my belly, where the lulu pants did not as I got bigger.
The only maternity jeans I bought... great price point and I love the distressed look.
I wore this dress to a few holiday parties, a bachelorette and also out to dinner with a cardigan over it.. I did have it hemmed right above the knee since I'm on the short side.
A few other things I loved that I don't see available... a gray t-shirt dress from ASOS and foldover yoga pants from Old Navy. I also bought a cute top at pea in the pod. One of the things that is noticeably missing is a jacket. I just didn't zip mine up if I couldn't and always wore a scarf. If you are in the city or outside a lot that probably isn't going to work for you but if you can get away with it, you'll save.
If you're expecting... congratulations! If you need registry tips, check out my post.