Has anyone else had little fluid around baby and what happend ?

Yesterday at my ultrasound the girl doing it was worried about the fluid levels around the baby and so was the DR when i saw her after.
My levels are at 7.4cm the DR did say if they go below 5 it's a worry. I'm having another scan on Saturday just to check the levels as they know they can go up and down at anytime. If they have gone down or the same it will mean even more scans to check things over.

Over the last 4-5wks my levels have gone from 16cm to 7.4cm with only once going back up a few weeks ago.