Mazal tov on your upcoming marriage!
Although there is a Biblical commandment to have children, and although Jewish law strongly encourages families larger than the minimum size, contraception is permitted under certain circumstances. A woman whose life would be endangered by pregnancy or childbirth is required to use birth control, in accordance with the principle that all commandments (except for the prohibitions against adultery/incest, idolatry, and murder) are suspended where life is in danger. Other situations, including the woman's physical or emotional condition and the family's ability to cope, may also be grounds for allowing contraception. Getting married at such an early age may prove relevant.
Each couple should discuss their individual circumstances with a rabbinic authority. If you do not have any such authority to turn to, you may contact us with further details for a specific p'sak from our rabbinic supervisor.
Feel free to write back with any further questions.