I'm getting the bunged upness, too! For some reason it's particularly irritating. Perhaps because it doesn't seem like it should be a pregnancy symptom?
I went ahead and bought a few maternity things. I'm on progesterone so I've got extra bloat and none of my size 10 trousers fit at the waist anymore. But I've already had 2 good scans, so I understand wanting to wait until you actually see the bambino.
For what it's worth, when you are ready to start buying, eBay has been amazing for really lovely, good quality maternity clothes at a fantastic price. I wouldn't have thought about going that route but decided to try it out after reading so many positive posts from other MNs who kitted themselves out that way.
To give an example of my success, I bought a pair of navy blue skinny mat jeans from Gap that were £45 (and they aren't cut well at the back waist so I'm forever pulling them up)...then I spent £44 on eBay (including s&), and got:
New Look dark skinny jeans, JojoMaman boyfriend jeans, Gap grey yoga trackies,
Gap black yoga trackies, Papaya white button down shirt with sharp pin-tucked pleating on the front, and a gorgeous Mamas & Papas grey wool shift dress. Everything is in like-new condition and arrived within 3 days. I bought my regular sizes they all fit. 6 lovely maternity pieces delivered to my door for only £44!
And oh my goodness, the first time you put on a pair of maternity trousers with a stretchy belly panel is amazing! 