When you first meet Rina and Hannah in their home, Rina asks for a semen sample and takes you to the bedroom to collect it. At that point, you can choose to refuse — she’ll get upset and run off. In that case, she disappears for a while, but she’s supposed to reappear at her house the next day, where you can apologize and continue the quest.
It seems like something may have gone wrong in your case.
Could you describe exactly what you did and under what conditions you gave her the sample? That would help a lot!