How much did you lovely ladies gain?

I’ve just had my 18 week appointment and I’ve gained 6.5lb!! Gutted! That’s means I’m the past 6 weeks since my scan I’ve gained nearly 4lb. I’m only allowed to gain up to 20lb my entire pregnancy and baby is still tiny!! Doesn’t help there were low ketones in my urine, we’re hoping it’s because we have swapped to a more healthy diet and my body is just adjusting (only been a week). On the bright side we heard the heartbeat and baby was super active 😊 Any advice or experiences appreciated!! Thanks ladies