I'm really scared has anyone else had this happen?

Okay, so today we had the ultrasound and, I have to have another ultrasound in 4 weeks because there's fluid in the brain, it was measuring at 10 which is the highest possible normal reading, and the doctor just wants to make sure the fluid doesn't increase. If it does increase I'll have to see a high risk/specialist, but at this moment in time it was the only abnormality and it wasn't actually abnormal, he just wants to make sure the fluid won't increase.