There could be a few reasons. One could be that fans are really passionate about the show and want to take it in a more mature or risque direction. Another reason might be that they think it adds an extra layer of drama or excitement to the original story.
Maybe it's to create more tension and emotional depth in the fanfiction. Pregnancy often brings a lot of changes and challenges that can drive the plot forward.
Maybe Clay's suicidal thoughts in the fanfiction stem from a build-up of stress, internal conflicts, or feeling hopeless about a particular situation. Different authors might have their own creative explanations for this.