Before 50mcg levothyroxin my tsh level was 3.23, new tsh level after 2 mo. of meds is 1.42. should my dr. up my medicine?

Not necessarily but: I feel one should adjust thyroid dose based on symptoms and levels of Free T3 (liothyronine). Many do benefit from doses that result in lower TSH levels- before doctors depended on TSH the average dose prescribed was double current averages! See http://www.nahypothyroidism.org/how-accurate-is-tsh-testing/ and http://www.thyroid-info.com/articles/david-derry.htm and see a doc who will test Free T3 (liothyronine) etc.