What would the world be like without birth control?

Answer 1

Even more over-populated than it already is.

Far LESS populated. Due to barbaric homebake attempts at abortions killing maiming and sterilizing women, huge infant mortality rates, huge maternal mortality rates, a constant oversupply of males with no access to personal sex partners 'competing' to the death (wars, duels, fights, brawls, etc) for the few available mates, and massive epidemics of disease as 50+% of the male population is "served" by barren (infertile) prostitutes constituting 2-3% of the female population.

In other words, we'd have something sorta like... well not sorta like, but 100% exactly the European middle ages. Btw, Rome fell because of the collapse of the crop of a plant contraceptive - it drove up demand, the plant was harvested to absolute extinction as prices rose, and a society that suddenly lost control over its reproductive fate quickly reverted to barbaric feudalism, lost almost all trace of culture and civilization, and "went feral" - for about 1500 years.