Dress for a christening

[SweetPeaPods]

Ds is getting christened in April. I will also be 16 weeks pregnant with dc2. I need a dress but I'm not really sure how big I will be. I've not lost all the weight from ds yet, who's nearly 8 months. I'm normally a 10, but currently a 12ish. I don't think I'll need maternity yet so maybe a size 12 with room? I don't really want to just look fat iykwim? I bought a few dresses from coast sale but I'm not sure if they will still fit. I got Chester, LaGuardia and Alba sleeveless.
Any ideas? I don't really fancy looking for a dress in the week before as I'll be back at work so trying to get as much as possible done while on mat leave.

Anyone?

I most definitely needed maternity at 16 weeks with DC2, TBH a lot of women do, especially if there is a small age gap between DC. Buying non maternity in your current size, a couple of month in advance would seem like a big risk to me!

What sort of styles, colours and budget are we looking at?

Any style that makes me look pregnant rather than fat, don't mind colour as long as its suitable for christening.
Budget of 100 possibly, ideally less as I might need new shoes too.
Thank you.