It sounds like there are pleanty of fox with no calling pressure. My opinion......I think you could safely go back the next day but at a diffrent time, say an hour or two earlier or later and still be successful without over hunting it.
If the area has pressure and calling them in is hit and miss, I usually will only call a spot once a week. I like to give it time to calm down and allow them to relax from being fooled the first time.
Remember, everytime you call or shoot a fox, he gets a little wiser!! I would also recommend that sopt to experiment with. Try new sounds to see what works.