I was back in maternity bras by six weeks, the girls were escaping from my regular bra and it's not like they were small to begin with, on the plus side DH looks like a kid in a candy shop! I got a pooch tummy at about the same time and it hasn't gone away, I actually look as pregnant now as I did at 23 weeks last time (I still hadn't really popped) and am in maternity trousers and skirts. I haven't resorted to bump bands yet because I've managed to use over bump stuff mainly, but I'll be digging them out over the weekend so I can wear some of the prettier stuff I have.
I second eBay for cheapish stuff, I got two maternity shirts for 99p (£2.50 postage) last week, I'll probably need bigger ones for later on, but I'm happy getting 2nd hand for now, I also picked up a lovely Mamas & Papas dress for £5, never worn and has a belt so it can be worn without a bump too!