TTC without thyroid/taking Synthroid

Amanda
I had a thyroidectomy 8 years ago and have been on Synthroid since. My levels have always been consistent and have had no issues. Dr says as long as levels are normal this shouldn't affect TTC. 
​This month dr said my I was slightly over stimulated (HYPERthyroid) and they wanted to lower my dosage. I'm not wanting to as it will be first time adjusting it and I've heard being slightly hyper helps when TTC. 
​Anyone TTC with the same situation? Curious how/if it all affects cycle and TTC? Thanks!!