The ornamental design for a pen or pencilcap, as shown and described.
FIG. 1 is a side view of the pen or pencil cap, the opposite side view being a mirror image;
FIG. 2 is a front view of the pen or pencil cap of FIG. 1
FIG. 3 is a bottom view of the pen or pencil cap of FIG. 1;
FIG. 4 is a first perspective side view of the pen or pencil cap of FIG. 1; and,
FIG. 5 is a second perspective side view of the pen or pencil cap of FIG. 1.
The broken lines shown in FIGS. through 5 are included for the purpose of showing portions of the pen or pencil cap that form no part of the claimed design.