just from the current trend, it's predicted world population will peak at around 9 Billion by the late 21st century, and actually decline by the 22nd (my guess is that it would level out from here).
Let's also keep in mind that more modern and advanced countries tend to have less children per family.
Also, there's an article that showed that we could cram every single person on the planet (right now) into an area about the size of Texas and it still wouldn't be as densely packed as NYC...so, I really don't think room and resources are going to be an issue.
I say life begins at conception, and that abortion is an act of violence and should be considered murder in all cases except for when a mother's life is in danger (tubal pregnancy, for example).