You are actually measuring the magnetic field produced by all four sides of the loop of wire.
(a) How would this affect your data compared to that produced by a single isolated long conductor?
(b) Would the field produced by the upper and lower wires be more or less significant than that produced by the field on the other side of the loop?
(c) Where would the affect of the wire on the other side of the loop be most noticeable--points closer to the front wire, or farther away?