unexpected ultrasound

Kassie • ~pregnant w/ first baby ~happily married 5 years ~been with my husband for 7 years ~we can`t wait to be parents~
Yesterday I was getting my daily IV infusion (I have severe hyperemesis) and they hooked me up to the monitor because I had been having contractions-- turns out baby girls heart rate wasn't tracing like they wanted it to so doctor ordered an ultrasound -- I was so excited I got to see her again (last time was 20 weeks) -- but then after the ultrasound my doctor informed me that I have excess amniotic fluid and I now have to have weekly ultrasounds to keep checking in on her-- obviously I googled (worst idea ever) but the doctor told me she truly believes that since it was detected this late in the pregnancy (35 weeks) that she thinks its idiopathic (no known cause) and doesn't think the baby or I will have any serious issues!! I am still naturally freaking out-- has anyone else experienced this?! 
Here's a nice picture of our sweet angel from yesterday