The ornamental design for a pen with tape measure, substantially as shown and described.
FIG. 1 is a front perspective view of a pen with tape measure showing my new design;
FIG. 2 is a front elevational view, the rear view being a mirror image thereof;
FIG. 3 is a left side elevational view, the right side being a mirror image thereof with the exception of the tape dispensing opening; and,
FIG. 4 is a top plan view thereof.
The tape measure structure depicted by means of broken lines In FIGS. 1 and 2 has been shown for illustrative purposes only and forms no part of the claimed design.