Thyroid is a gland which is present in every individual and it's main function is to produce an important hormone called thyroxine.  This can go up and down which can then have an impact on pregnancy of not properly managed. In your case TSH appear to be well with In the normal range . Hence I don't see the need to do anything else at the moment but the need to have your thyroid profile checked every 4-6 weeks to ensure it remains normal.