What might be the next step: Infertility?

I posted this last night, so sorry for the repeat. I posted it so late though, so I only got 1 helpful response. I would like to see what others have to say as well, so I deleted the other one and I'm trying again.

My husband and I have been TTC for over 3 years and I was diagnosed with PCOS and hypothyroidism earlier this year (did not seek Dr help until this year).

RE put me on medication for my thyroid and I was on birth control for 10 weeks over the summer to lower my testosterone. I just started my 3rd round of letrozole yesterday. At my last appointment (August, right before my first letrozole cycle) she said we would do 3 rounds and if I'm still not pregnant, we will reevaluate and go from there.

What might the next step be though? I know it's based on each individual case, but I'm curious what the possibilities are.