It is important to consult with your healthcare provider regarding your thyroid levels during pregnancy. A TSH level of 0.20 may indicate hyperthyroidism, which can have potential risks for both you and your baby. Your healthcare provider will evaluate your overall health and symptoms before deciding whether to retest or start medication. They may consider factors such as previous medical history, current symptoms, and other thyroid function tests like free T4 levels. It is crucial to follow their guidance for the best course of action in managing your thyroid health during pregnancy.