MFP Calories & Fitbit Force

I just linked my MFP and Fitbit Force. I have no idea how to enter my goal calories to make sure that my calories are accurate at the end of the day. Would you set it at sedentary and then just eat the exercise calories? I want to make sure that I am eating the right amount, but not too much, as I am 16 weeks pregnant.

Thanks for your help as I get the hang of this new tool!