Hi, I Am 39 Years Old, My Gynae Put Me

Hi, I am 39 years old, my gynae put me on eltroxin 50, I had a miscarriage at 9weeks earlier this year due to untreated hypothyroidism, I had d and c, but since April I have had hard time falling pregnant again, I have been on eltroxin for almost two months now, my period is irregular by a day or two, I have never had irregular period before, I also easily fall pregnant earlier this year by tracking my ovulation, but now it's a bit difficult..Will eltroxin cause this, Will I have a problem conceiving with these meds