The Torah-level mitzvah to procreate is to have one boy and one girl. As you describe, it is difficult to fulfill, given that we do not control gender selection of our children. Even so, in striving to fulfill what Hashem wants, we are on much firmer ground following halachah than speculating.

Halachah does allow for contraceptive use in specific cases. For example, many rabbis permit contraceptive use for years between children to facilitate their care. A lack of finances and a feeling that one's hands are full are two other factors that could lead to a permissive ruling on contraceptive use. Views vary on this issue. If you would like an individual ruling from our site's halachic decisor, Rav Yehuda Henkin, please write back with a little more information about these factors and any other concerns that may be relevant, such as your age and marital situation.

It is also worth noting that a decision to use contraception now need not be a binding decision never to have more children. Your circumstances might change, as might your thinking.