i've started pregnancy yoga too, and having always been rubbish at yoga, it's perfect for me, and i think i would even do it if i wasn't pregnant! i feel terrific afterwards too.
My weight gain is about 5 kg (11 pounds) at 22 weeks. Had my scan yesterday, which was very exciting. Tried my hardest to guess the gender, but the image was too grainy and disjointed, and frankly i thought the head was the belly until told otherwise. Otherwise, the doc said the baby in a breech position, but from what i've read, that isn't something to worry about at this stage.
Otherwise, has anybody been needing the toilet constantly? I went to the cinema, and i had to leave to pee four times - and they say get to the cinema all you can before you have the baby!
Re iron, i was told that dried fruit, such as apricots, is brilliant for supplementing depleted iron stocks, but probably more for those who have reasonably normal levels anyway.
Anyway, good luck to all those yet to have their scans.