Subclinical hypothyroidism and ttc baby #4

Just found out I have it. I have had 3 healthy babies before. Youngest being 18 months

Could that hinder trying to conceive ? I just started trying and wanted my yearly blood work before I did and...

TSH was 6.4

Free T4 was 1.14

They started me on 25mg of Levothyroxine

How long do you think it takes to get to the normal range? I get full blood work in 4 weeks