Are ovulation tests permitted on Shabbat? (You pee on them and lines appear, like a pregnancy test). What about for someone just tracking her ovulation but not planning to conceive this cycle? (preparing for IUI/etc) Color appears almost immediately but you wait around 5 mins for the final results.
If this is to serve the goal of conceiving then it is definitely ok. This is a large צורך מצוה. *Definitely mutar.* Although it possibly does not have a grama dimension, it is still, in my opinion, תרי דרבנן (disposable; not interested in a result of a colored object; causing a chemical reaction to lead to coloration, but not actually adding a dye or coloring agent). This is definitely mutar for the sake of פרו ורבו. If you want to be more machmir, then urinate into a cup, and put the stick in the cup with a shinuy (e.g., your weak hand).