How to get pregnant? a tutorial please!
Join the Dahlia faction when they invite you, do a few quests, then the quest to unlock pregnancy will appear, unlock pregnancy by talking to the doctor (one for each char) but that wont actually unlock it yet . You have to progress until you fight the student council president after which you cannot go back to the academy. Afterwards the pregnancy can progress by just walking you'll get a notification when the fertilization occurs and when it progresses to the last month.
CORRECTION: Pregnancy not tied to route. It's available to both academy and Dahila route with different scens for both.
At the last stage you won't be able to switch characters, all H-events bar a few pregnancy specific ones are locked (afaik there's just a couple for each char
selling breast milk, anal, vaginal and some exhibition scenes that have pregnancy variants) it ends when you go to the hospital to give birth. All in all, a very underwhelming pregnancy "mechanic" but pretty much expected from oneone1.