Reference: Fataawa Mu’aasirah – Page 80
al-Mowsoo’ah – 3767
Question: Is it impermissible to prevent a pregnancy for a period of two years at the beginning of a marriage, so long as both husband and wife are in agreement with this, such that they can both see whether they [are compatible] to continue with the marriage or not?
Response: This is not impermissible, however it is better not to prevent [a pregnancy], and they should join together in good and have good suspicion [about their affairs] in [the Hands of] Allaah.