Hi I hope someone might be able to give me some advice. Me and my girlfriend are trying for a baby but I have just found out my thyroid is under performing (9.6 somethings instead of 12 somethings I think). I read that this can affect my fertility and have done an over the counter fertility test and it said I have a low sperm count. Bit bummed about that. My doctor started me on 50mg levothyroxine two days ago, but he doesn't know anything about thyroids and fertility. Does anyone know how long it takes to start having a positive effect on sperm count (if that is actually the cause of the problem)? Please help.