Ladies: If children are a gift from God what is the purpose of birth control??

ok people always say how children are gifts from god...if this is so then why do alot of ladies resort to birthcontrol so that they can stop the delivery of the gift that God has for them??? I mean come on birth control has alot of side effects and you C an still get pregnant while on it...so why stop your gift from god????? SERIOUS ANSWERS. ims & emails accepted.