Under active thyroid

We've been ttc for 14months. I went to see my dr recently and he recommended that I have blood test done on day 22 to check I was ovulating (which came back normal) and then day 2-5 during my period to check the other hormones that could affect me not getting pregnant. My dr rang me just a 2 days after having the second blood test to tell me that I have an under active thyroid and that I will need to take medication for it. I just wanted to see if anyone else had this problem and how long it took them to conceive after they found out? And maybe if there is anything else that I can do to give me a better chance of getting pregnant? 

Many thanks in advance!! X