It has been approx 4 weeks. It does seem that the left lobe has some function or your TSH is being suppressed in some way. You can not rely on TSH alone, ESPECIALLY since you only have half a thyroid. Look over this post: Thyroid care concerns around the world - week 2
In particular the last two right now.. 36 and 37.. I believe. There are too many issues that can cause interference with the TSH. You must keep an eye on TSH, Ft3, and FT4 every 3 months minimum if you feel optimized on meds or have had a partial thyroidectomy. My mom had a PT and the Endo/Surgeon dropped the ball. She suffered 10 years hypoT.. because the MDs only checked TSH.