Hypothyroidism and ttc

Charlie • Avoiding pregnancy tracking my cycle
I have hypothyroidism and plan to start ttc in March, I'm currently on the pill, my question is for those who also suffer how soon before ttc did your dose change? I'm currently on 50 of eltroxin (levothyroxine sodium) I don't feel like I have anything wrong with me I feel normal, I had my thyroid checked as all my sisters (5) suffer so I knew I had to as well, I lost a huge patch of hair so that's how I found out I had it.
Any info on it and ttc with hypothyroidism.