assalaamu alaykum shaykh
i have kept mannat for child by fasting in the name of 16 [private], on every 16th islamic day i fast, give fatiha snd narrate 16 [private] story, but due to menses i m not able to fast on this 16th. Will i face any problem or any diff way?
No worries. You will not be tasked for not doing an intended voluntary good deed, especially if the reason you are prevented is outside your control.
Hajj Gibril Haddad