The key to conceiving with thyroid is keeping your TSH levels in the safe zone, usually below 2.5 for pregnancy. Get your levels checked and talk to your endocrinologist for the right dose.
Having hormonal issues like thyroid or PCOS can make tracking ovulation a bit tricky. Just be patient, work closely with your gynac, and keep your medication regular.
I just had my baby and I was on thyroid meds throughout. I conceived within three months of getting my TSH levels under control, so it's totally possible!