What Happens If You Get Your Period before Iftar?
Question

If you are fasting, and you get your menstrual cycle at the last five minutes before iftar, do you still have to break your fast?
Praise be to Allah.If the period begins before sunset, even if it is a moment before, the woman’s fast is invalidated and she has to make up that day. 
Shaykh Ibn ‘Uthaymهn (may Allah have mercy on him) said in Majalis Shahr Ramadan, p. 39: 
“If the period begins whilst she is fasting, even if that is a moment before sunset, her fast is invalidated and she must make it up. 
It is not permissible for her to fast when she is menstruating; if she does that, her fast is not valid.” 
Ibn Qudamah (may Allah have mercy on him) said in al-Mughni (4/397): 
“If a menstruating woman intends to fast and refrains from eating and drinking even though she is aware that this is haram, she is sinning and that will not avail her anything.” 
And Allah knows best.