TSLM, I'm normally a size 18 and in size 18 maternity (except for my enormous size 20 knickers at the mo, they're fab!) but size 18 over bump jeans are digging in at the top now too. So I'm normally a bigger girl, and the doctor at the hospital didn't seem to think there'd be a problem with chunkiness.
As for your needle phobia, even though I inject myself 4 times every day and numerous finger prick blood tests, I have a massive phobia about 'proper' blood tests as a result of it taking 4 adults to hold me down to take blood when I was 3. The needles they use in acupuncture are so tiny they just feel like you've been bitten by an insect for a few seconds, if you wanted to give it a go, you could ask whoever does it to just try 1 needle to start with to see how you cope before you commit to the treatment. Honestly, if you keep your eyes closed like I did, it really didn't feel like needles, just a tiny scratch. And I'm a naeedle expert!!