I'm just on 23 weeks and I think I've put about 6kgs from my normal weight. I did lose 1kg with m/s so I've put on 7kgs in total. And probably 5 in the last month (not my fault, I went to visit my mum and was feed every hour!!)
My ob said ideally put on 0.5kg a week. But who knows what I'll end up at 40weeks. My friend hardly put on anything at 30 weeks but at the last months she was putting a kilo a week and ended up with 20kgs. She had her bub in Feb and has lost 10kgs since (and she couldn't bf).