Was anyone else told they have slightly increased amniotic fluid in their scan?

Fay

I had my detailed anatomy scan yesterday at 20 weeks and 3 days. Everything appears good with the baby, but I have a slightly higher amniotic fluid than average (told AFI of 21, when average is no more than 18). Has anyone else been told this too, or experienced it in previous pregnancies, and what was done about it etc? This is my first pregnancy and i’m a bit confused and worried.