Hsg vs hysterosonography

I just had my first appt with RE today and she wants me to do either HSG or hysterosonography. HSG would be covered but id have to pay for the ultrasound. She said I could do either and she had no preference. What have you done and are there any benefits to one over the other? I'm happy to pay out of pocket if I need to. I read that HSG is more painful but maybe gives more info about the Fallopian tubes?? Please help if you've had either or any information. Feeling so overwhelmed and I can't remember half the stuff the doctor told me.