This is going to sound dumb, but I don't have a pregnancy wheel calculator on me at the moment. I will try to get my hands on one and do your calculation. In the meantime you could call your doctor's nurse or your hospital's labor and delivery. All they need to do is put your due date on the wheel and go backwards. (They will know how to do this).
You can also guestimate by subtracting 11 weeks from today's date.
Sorry not to be more helpful--I'll try to get back to you!