wedding wear options for older and mature brides

Hello ladies I need advice are there any mommas that have hypothyroidism and on synthroid and gotten pregnant? What was your pregnancy like? How was your child effected? Heres a lil history sorry for long post
I have a 5yo son who took 6 yeara to conceive because of health issues ect. I found out i was hyperthyroid when I was pregnant fast forward after birth my thyroid became worse. I was never medicated and it became bad I had radiation twice on it this past December was last time ans have sense been hypothyroid and on 100mcg synthroid my OB I saw last week says now that my levels are stable I can try again but im worried. Also I will be 30yo next week. My son wants a sibling badly but I fear the gap in age will just be to hard. Any advice would be appreciated. Also should I start prenatals now to help my chances? Experience? wedding wear options for older and mature brides