I want to ask you regarding ending the sehri. In my area they announce that ppl stop eating, time for sehri has been finished. Then after some moments azaan gets started. Today i swallowed some water even after listening to announcement but stopped before azaan started. Is my roza valid?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

The real time for refraining from whatever breaks the fast is the beginning of the true dawn, as Allah Says (what means): {And eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night].} [Quran 2:187]

There is no consideration to the so-called end of the timing of Suhoor (the time to stop eating and drinking and the like before the Fajr time) which determines the time of makes the fast start few minutes before dawn. If a person eats or drinks after this time, his fasting is valid as long as he stops eating and drinking before dawn (Fajr).

Therefore, if the Mu'aththin (the person who calls the Aathaan) in your area calls the Aathaan (call to the prayer) at the time of the beginning of Fajr, then your fast is valid, and you are not required to make it up, because you do not have to stop eating and drinking according to that announcement of stopping to eat and drink.

Allah knows best.