I've put on at least half a stone, so probably about the same as you. I have been lying in bed a lot for the last few months (still only 16 weeks here, too!) as I have felt so tired and dreadful, but funnily enough I was eating loads as well, despite feeling sick.
My last two pregnancies were different in that I hadn't got very good medication or coping skills so I ate very little till about now when I suddenly started to be able to again, and thus lost weight both times. But then I had a catch-up, with my second at any rate, and put on the right amount afaik.
This time it has been consistent weight gain and I am a bit worried that I will keep putting on loads till I am a moving mountain. I'm just over 9 stone at a guess, was 8 and a half before, and 5ft7.
I think though that I have very little control at the moment over what I eat - it's a case of coping with feeling rubbish, and so whatever it takes, whatever I can manage I will eat. Hopefully as I feel a bit more normal I'll be able to forget about eating and food more and more, like I normally do, and it might slow down a bit. It is such a luxury not to have to think about the next thing to eat all the time!!
(NB my ancient pregnancy book says that weight gain over about half a stone in the first half is 'undesirable'
. And all the other advice says it's unfortunate if you lose weight in the first half...you cannot win!)