Weight gain 5 months

Hello ladies. I'm just wondering how much you gained by month five. I'll be twenty weeks pregnant at the end of this week and i've gained about 4kg (nearly 9pounds). Started off at 54ish kg (119 pounds) and I'm now at 58 (127.8). I'm pretty short so that should count in there too. I'm a little worried I'm not gaining as much as I should... Some help for my peace of mind would be appreciated. Thanks