I've been a bit wary about offering a seat since I asked a lady with a bump the size of a football if she wanted mine, and she announced very loudly "I'm NOT pregnant, you know!"
Everyone in the carriage was sniggering and I was mortified. If that had been me, I'd have just said thank you very much and sat down fast...
The other night I was asked to give up my seat on the bus by another pregnant woman. She wasn't very pregnant - showing a bit, but making the most of it, and obviously on her way to a night out. WWYD? I'm now 17w, but still wearing pre-pg jeans, so I know I don't look properly pg. I was probably further along than she was (not meant in a rude way, but what I mean was that you'd do a double-take before offering a seat, as you wouldn't be sure - she wasn't about to pop or anything). And I was knackered - it was 9pm and I'd just finished teaching the evening class, on top of my daytime classes. I did get up, because I didn't know how not to, without being rude. Fortunately a bloke looked at me and said "you look even more tired, take my seat" - which was so sweet. I was so grateful I nearly cried, and just told him I was 4m pregnant as I thanked him. There are some nice people out there, honest, and he didn't even know I was pg!
But honestly, what would you do if you were asked for your seat by another pregnant woman? (assuming she's around the same stage, not one who's obviously due in the next four weeks, when there's no contest!)