Yes, this is possible.

This can be entered in the Remark field.

Remarks already used will appear in the list.

When the remark you want to use is not there, click on the magnifying glass at the right of the field.

In the screen that is displayed now you can add a new remark by clicking on Add remark.

You can now enter a description and an abbreviation.

Next click on Add and select. The remark you just created is immediately added to the pregnancy check.