Is my fast acceptable if I drink water after hearing the Fajr adhan, upon uttering the Shahada?

If the muezzin does not call the Adhan until after the time for Fajr has begun, then it is not permissible to consume things that break the fast once his Adhan starts. Whoever consumes them will have their fast invalidated and must make it up, for Allah Almighty says: "And eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night] from the Fajr." However, if the muezzin calls the Adhan before the time for Fajr has begun, then there is no harm in eating and drinking during the first Adhan, for what matters is the true rising of dawn.