during Fajr salaah, I unintentionally burped while in sajda and some water came up. It only came up to the throat but did not reach the mouth

Assalamu'alaykum Mufti Saheb, this morning, during Fajr salaah, I unintentionally burped while in sajda and some water came up. It only came up to the throat but did not reach the mouth. As I was in sajda at the time, due to the small amount and the fact that it had not entered my mouth, I swallowed it again so as not to release it onto the masjid floor. Has my fast been invalidated and, if so, what do I need to rectify it? Jazaak Allah for your help.