Tyroid during pregnancy!

Berenice • I'm 23 mother of two beautiful girld 7,4 year old ...newborn baby jonathan born July 3rd 2016
Just got a call from my OB saying that my thyroid is in the "high normal" and want to put me on low dose meds i have no idea what this means or what risks there are to baby and myself :( i have apt on Monday if u know anything about this would help..