Good morning moms! I'm wondering what everyone's thoughts are on my current situation please

I'm 29 weeks along and have an interview scheduled 10 days from now for a promotion at the company I've been at for just over 2 years. It's a large company (5000+ employees) and in joining the company I took myself down a career track parallel to, but not identical to that that I had imagined for myself. My current position transitions well into this newly created position and I'm qualified and (in my opinion) a great candidate for it...except that I would be accepting the role at approximately 32/33 weeks pregnant.
In my current position, I intend to work until my son arrives and then to return to full time after my 12 weeks FMLA/maternity leave. The promotion is for a newly created position that is being filled to "get ahead of the game" as it were, and is not something that will be immediately vital and I feel I can catch it up after my time off just fine. Of course, that's not really up to me though. If offered the position, I would be flexible about returning before the full 12 weeks, but either way the company will be paying for my maternity leave - it's just at what rate and for how long.
Also, I started as a bit of a bigger girl, and have found an interview outfit that, while professional, allows me to appear possibly just fat instead of obviously pregnant. While I don't care to hide it day-to-day, I don't see the people I'll be interviewing with around the office and they don't know my condition and I feel allowing them to see my bump obviously may cause them to...listen differently? (Interview panel is one female HR and 4 male directors/potential new bosses.)
Sorry so long, but I wanted the background to be there to answer my question - would you ladies disclose the pregnancy openly at the interview, or have a one-on-one after an offer is made but before accepting to be sure the new boss knows I'm not trying to be deceptive and that I have a plan? (Any other thoughts are welcome as well!)
Re: Interview for promotion at 7 months?