If the period started before magheeb adhan then your fasting is not valid for that day.

If I fast and then in the afternoon my periods starts then is my fast still valid for the day?

Fasting | June 2, 2016 6:13 am
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I had acid reflux while I was fasting and some vomit came up to my throat. Thinking that it wouldn’t invalidate my fast I swallowed it and then I tried spitting whatever had come up out. Is my fast invalidated because I swallowed it? It wasn’t uncontrollable I could have spat it out but I swallowed it.

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If a person has severe acid reflux & whatever he eats comes up & goes in like (reflux) all time. . he still wants to fast Ramadan. . After having sahar, when he goes for fajr in masjid, hes afraid he might spit all while performing salah, is it permissible to begin fasting after he came back after fajr? Is he sinful if he doesn’t fast?