Meredith gets pregnant at the beginning of Act II - Affection must be 17+ic... so the walkthrough is a bit out of date? If its just random... does that mean if you are unlucky you might never get them pregnant?
Ruksana will get pregnant after the scene with her in the castle torture chamber (second floor) - you have to choose to have vaginal sex.
Clawyn's begins with a meeting in your bedroom where she asks if you want to have a baby. If you say yes, then later she will again meet you in your bedroom and inform you that she is pregnant. Eventually she will again be back in your bedroom for a scene while she is pregnant.
After Meredith & Ruksana get pregnant you need to go and complete a "task", then return to the castle. For Ruksana you will receive a notification that she wants to meet. For Meredith there is not notification, you just need to go back to the garden house and talk to her.