The ornamental design for a heatingpad, as shown and described.
FIG. 1 is a top perspective view of a heating pad, showing my new design;
FIG. 2 is a bottom perspective view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a bottom plan view thereof;
FIG. 5 is a front elevational view thereof;
FIG. 6 is a rear elevational view thereof;
FIG. 7 is a left-side elevational view thereof; and,
FIG. 8 is a right-side elevational view thereof.
The broken lines showing a power cord in the figures depict portions of the heating pad that form no part of the claimed design. The remaining broken lines represent stitching, and are part of the claimed design.