Hello I appreciate your query. First, about your thyroid issues. Maintaining TSH ideally to less than 2.5 in the first trimester is important for the baby s development, as thyroxine is a critical hormone in development of the baby s organ systems, particularly the brain. Hence, ideally, you should not titrate your dosage by yourself, but consult an endocrinologist, who would go for regular tests, and accordingly adjust your dosage. Sefstart is the brand name for a tablet which contains folic acid, methylcobalamin , pyridoxine and DHA. All these are essential vitamins and substances critical for the early development of the embryo. Your gynecologist must have scheduled you for your next visit after 15 days, hence the prescription must be for 15 days. Pregnant ladies need folic acid supplementation in order to ensure complete embryonic development. Hence, please do take the tablets as advised, and consult your gynecologist again on the recommended dates. All the best for your pregnancy.