Hiya - thought I would "weigh" in on this debate Sorry, I am in a silly mood. Seriously now...................before I fell pregnant I was 58kg and 162cm. I lost a couple of kilos in the first 12 weeks and was back to about 56kg. I stayed this weight mostly until my 20 week appointment and I was 60kg. So I had put on 4kg in the month since my last Ob appt. It was over xmas though so I wasn't too worried. Then at my next appt after that I had put on another 3kg! So that was 7kg in 8 weeks. I have another appt tomorrow and I weighed myself last night and I think I have put on another 3kg, but that's in 3 weeks. So seriously that is 10kg in 11 weeks. I weigh 66kg - the heaviest I have ever been in my entire life. OMG And I am only 28/29 weeks so still a fair while to go which means alot of weight opportunity OMG AGAIN

So to respond to your question, I wouldn't be too worried unless your midwife or Dr mentions something. It is still early days yet and hopefully for you, you are one of those lucky ones that only puts on a little bit.