Low T3, normal TSH and T4

I recently got back blood test that indicate my T3 levels way below 'normal' and my TSH, T4, and antibodies at a normal range. My body Vitamin D levels are also way below normal (and I get plenty of sunshine and take supplements). I have been on Levothyroxid (sp) for several months now.

To give a brief background, I have shown symptoms of low thyroid for years and have just started treating it with T4 meds this year. Past symptoms include hair loss, depression (which I have been medicated for), IBS, anxiety, sore joints, excessive tiredness, weight gain, dry skin, low sex drive, I get a cold or flu on average 3 times a year, etc. I could never pinpoint anything and just go about feeling not right to down right miserable and complaining about having the worst immune system in existence. The meds have helped a bit but something is just not right.

At the moment, I am pregnant and due within a few weeks.

My doctor insist that I may be able to get off medications completely. I can not find a whole lot of information on this type of combination of lab work results. Any advise or insight would be appreciated.