Pelly,
You ask a lot of questions that should be fairly easy to discover the answer by reading a good Catechism. I would suggest obtaining a copy of The Catechism of the Council of Trent and even The Catechism Explained by Rev. Francis Spirago and edited by Rev. Richard Clark (Spirago-Clark). It seems that you really need to learn the basics of the Faith.
To answer your question, the answer is no. Baptism cannot be performed before the birth of a child. To follow up, the Church used to recommend instructing women in the correct method of baptizing babies in case there was a danger of death of a newborn infant. Of course, this was at the time that childbirth was strictly a women's issue and midwives generally attended the births of children. Today, when fathers (or other relatives) often attend a childbirth while a doctor actively receives the baby, everyone should know how to baptize in case it is necessary.
When my third child was born, there was no immediate danger of death though baptism had to be delayed for about 3-1/2 weeks. While at home, she stopped breathing for a lengthy period of time and was hospitalized for a time. I ensured I had a cup of water on hand at all times in case baptism became necessary. I almost did baptize her but delayed because, by the time I had the water ready, she had already become stable and breathing.
(For those who are getting ready to condemn me for waiting 3-1/2 weeks, please note that the Novus Ordo parish I was in would only baptize the last Sunday of the month and she was born during the first week of the month. I didn't know any better at the time.)