Because the child would probably already be born. It would perhaps already be grown up, and the pregnancy test would lose its meaning.
I was just thinking that it might have some meaning if the child was already born but still an toddler. Then it would probably be the pregnancy test for Nicole/Envy. So from Sage, we know that when she came to the HOTs, there was a sister that Sage did not get along with. The time frame also includes the emergence of the DIKs and their tradition of sperm petition.
What if the DIKs did their first cum petition with HOT girls and one of the girls was Nicole/Envy. She was impregnated and subsequently dropped out of college. Since she had no education, her only option was to work as a stripper. Now she may not even know who the father is, and there are four candidates for that. Tommy, Rusty, Nick and Vinny.
This could be an interesting story.