Working out but TTC

Kat
I live a pretty healthy lifestyle. I have always gone to the gym at least 4 days a week and would always push myself really hard. Now that I'm TTC I've limited myself to 3 days a week and I'm struggling trying to figure out what is too much for me to do. I am scared to run too much or do conditioning. My workouts have been suffering but I want to make sure I'm not over doing it so that I can get pregnant. I have a low to normal BMI. Anyone else struggling with this?