fluctuating tsh

my doctor has been monitoring my thyroid for awhile. i was considered borderline hypo with my tsh ranging from 2.6-3.3 I was treated with synthroid during my pregnancy which stabilized it to 2.0-2.2 and then after tapering off it months after giving birth I was back to my normal 3 range. in June 2012 it was 3.1. today almost a year later it's at 1.6 ??? it wasn't even that low when I was being treated during pregnancy a couple years ago. I'm curious how much fluctuation is "normal" ranging from 1.6-3.3 technically is the normal range but is it really normal? of course I am following up with my doctor I'm just curious about it... any thoughts?

Hi, mine fluctuated also after pregnancy but much wider in the numbers. I was 0.63 in January and 7.3 two days ago...so I just started Synthroid 7.3 mcg today. I have been checked for the antibodies and have both hyper & hypo antibodies and unfortunately have bad symptoms of both for almost two years now..it has not been fun so I'm praying the Synthroid will level out my tsh & help releive my symptoms.