Worried I'm gaining too much too fast

I'm a little over 18 weeks and I've gained close to 20lbs since I found out I was pregnant at 4 weeks. I'm worried that's too much since doctors only want you to gain 35-40 the whole pregnancy. I don't eat unhealthy all the time, just have days where I splurge. I try to always eat fruits and veggies and I work with kids so I'm moderately active most days. I drink water ALL the time and lots of it. I don't know if there is anything I can do to maintain weight at this point. I'm worried about passing my glucose tests, etc. Anyone else feel like they gained a good amount in the beginning but had a normal, healthy pregnancy?