Here are some more details to your questions
@shatinn 1. Just like Franki said.
2. You can change the name of sims in a household at any time by clicking on a dresser or mirror and selecting "Plan outfit" or "Change sim."
3. The post-woohoo chimes was a Sims 3 thing and don't happen in Sims 4.
In Sims 4, there are several ways to know if a female sim is pregnant.
*Watch the female. If she's pregnant she occasionally covers her mouth with her hand and acts like she wants to throw up or she might run to the bathroom and throw up.
*Have the female sim sit on a toilet and take a $15 pregnancy test.
*If you have seven sims in the house and your couple can't "Try for Baby" or adopt a cat or dog, then you know the female sim is pregnant.
*If you are playing the female sim and she does none of the above, she will automatically get an Eating for Two notice exactly 24 hours after she conceives (if you're playing on Normal lifespan).
4. Even if they aren't in the same household, the male sim's phone will ring when she has the baby. The male sim must then click on his ringing phone.
He will get a pop-up notice where the mother tells him the baby's gender and name.
Good luck and happy simming!