All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
The ‘Aqeeqah is a Sunnah and it is not an obligation according to the preponderant opinion of the jurists . Therefore, whoever buys an animal for ‘Aqeeqah and it died before slaughtering it, then he is not obliged to buy another one in its place.
In addition to this, slaughtering two sheep (or goats) for a newborn boy is the Sunnah but if one slaughters for him only one sheep or goat, then this is sufficient. Indeed, it is confirmed that the Prophet made ‘Aqeeqah for Al-Hasan and Al-Husayn with only one sheep for each one of them.
Hence, if you do not have enough money to buy another goat, it is better to take the initiative to perform the ‘Aqeeqah now, as you do not know what will happen to you or to this second goat in the future. For more benefit, please refer to Fataawa 81462 and 89873.
Allaah Knows best.