Correct, male or female have a much longer story.
In case anyone else has the same question, you can only do this if you killed Seraphina in Chapter 2 and have TF magic.
So for Rhelyla it turns out that the final scene was locked behind you taking her to the bar and having group sex with her. This wasn't intentional, but you should be able to see that scene by inviting her for "takeout". After seeing the bar/club group sex scene with her, you'll now be able to access the pregnancy scene.
Additionally,
, it will automatically fail. I actually wanted to make the conditions a bit more up to the player cause this kinda feels like to me that you're forced into it as long as you see the scene and have enough cum. As I personally don't like pregnancy content, I didn't want to force it on others. But Eins disagreed with me and since he wrote the scene I allowed it. So Rhelyla will always end up pregnant by chapter 4 by either the protagonist or the other guy.
If you're still having trouble or you just want a quick fix, you can upload your save file here or to the discord and I'll fix it for you. I already fixed it in the next update, so next month will reflect the fix, sorry about that.