I hear you with the swimming thing, Mellie. I learnt as an adult too, and am still rubbish - have never mastered breaststroke at ALL, and my front crawl is seriously crappy. Quite like backstroke but keep bumping into things! And I'm still slightly scared of the deep end.
Mind you, I'm pretty scared of exercise full stop, even when not pregnant 
Made a huge tit of myself last night. Heat was horrible, and the trains were well up the spout. I waited half an hour for a train that then got cancelled, and eventually had to tube it across London to get on a completely different train line. Which was also up the spout, so people were pushing and surging onto trains and it was like sardines. Once I'd got on the train, I went seriously wobbly and started shaking. I wouldn't have keeled over, because it was so packed there was nowhere to keel over to, but I really needed to sit down. So I said politely to the man next to me 'excuse me, would you mind giving me a seat? I'm pregnant and feeling a bit faint'. He completely ignored me, so I insisted, and he eventually gave me the seat. I was only going one stop, so he was only out of the seat for 10 minutes. I thanked him profusely when I got off, and said I was really sorry I'd forced him out of the seat, and he didn't say a word in reply. Then some twat on the other side of the train shouted 'You can have your seat back now, mate' and the whole carriage started laughing. As I got off the train shamefacedly.
. Now I just feel like I was being a melodramatic nob, and worried in case he was disabled or something (though if he was he could have said...)
When I was last pregnant I got used to politely asking people for seats, but that was when I LOOKED pregnant. I now know it's not acceptable to do it when you don't look pregnant!