I think early pregnancy is the hardest stage to dress. I'm 14.5 weeks along, and this is my second pregnancy, so I am definitely showing. But if I wear something that's loose, I just look...well, like I have eaten about 12 burritos. With extra cheese. It's not pretty. So in this stage, before the belly is literally ALL YOU SEE, my rule is to fake a waist by belting above the bump. By belting above the bump, you not only accent what's left of your waist (or fake that you still have one), you clearly look pregnant instead of chubby. When I wore this shirt suddenly everyone was like, whoa! You popped! But really, I belted.
Also of note, these awesome jeggings I'm wearing. Maybe you don't believe in investing a lot in maternity wear, and I am mostly 100% on board with you there. But there is one thing I do believe in: nice maternity jeans. I'm tall (5'9"), and I wear jeans several times a week to work, and on the weekends. For me, it's worth investing in a couple of pairs of high end maternity jeans. I have found the Paige brand works great on me (which is funny since when I'm not pregnant, I don't love this brand), and so I've bought two pairs off of eBay for less than half the original retail. There are great sales, too, as you can see here.
top: Old Navy 3/4 Sleeve Top (these are on sale right now and seriously awesome. I have 3!)
jeans: Paige Maternity Union Jegging (more than half off!)
scarf: J. Crew (similar on sale! here)
coat: BB Dakota (similar on sale! here)