Hi smiling.
(Sorry for long post, but I know how you must be feeling so have tried to give you as much info as possible. I am now 25 weeks)
I have one of these too. It was first picked up at an NHS scan when I was 14 weeks. I had already had a private scan at 11 weeks but nothing was seen then.
On my notes it says: '5.7mm thick amniotic band seen in lower segment of uterine sac. To review at 20 week scan and see consultant'.
At the end of the scan the sonographer kind of mumbled, oh by the way...You have an amniotic band. It's not causing any problems at the moment, but it could. This is my 4th DC and I had never heard of these before. So I was asking her loads of questions to which she just said " you will need to come back at 20 weeks and have another scan and see the consultant"....
So I went home and googled 'amniotic band' and was freaked out by horror stories so I tried to call my MW and ask her about them, no answer. In the end I was soo worked up I called the hospital where I had by scan and told them about the scan and the band and the fact I had been sent home and told to wait 6 weeks to see someone about it. They apologised profusely and said I should not have been sent home without a proper explanation. They arranged for me to come back the following week and see a consultant.
From looking at various websites there are 2 VERY different things:
Amniotic Bands and Amniotic Sheets or folds.
Amniotic sheets or folds are common and highly unlikly to cause any damage to you or the baby.
Amniotic Bands or threads are more serious, but extremely RARE.
Have a read of-good explaination : www.babycenter.ca/x559349/what-is-an-amniotic-band