Hello,
You likely wont feel infertile most times but fertile you can feel better as they are rounder.
If they are developed/calcified & have dropped you should be able to feel them in the center of the belly & many times see a visible outline of them if they are fertile.
You might not be able to feel or see infertiles though.
Be sure you have a laybox made for her in case she needs to lay.
Tracie