Low amniotic fluid

nikki

I had my anatomy scan today almost 21 weeks. My amniotic fluid was measuring "low" below their large scale "normal" I have to go back in Monday for another ultrasound to measure. Has anyone else had this? This is my 3rd pregnancy never had this issue, also a lot of contractions/braxton hicks( large enough to see during my ultrasound today) I never had with my previous pregnancies.