In Canada the mosque is the only place that women meet and every Sunday we have groups so we have many fatwas about the menstruation, some say that we can come to the mosque and it is permissible and the others say, no that was never allowed; so I'm really confused.
Please help me to understand and prove with HADITH.

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 majority of the Muslim scholars (among them the four Imams) are agreed that a menstruating woman should not stay in the mosque even if her purpose is to study or teach the Quran or other Sharee’ah sciences. Allah Says (what means): {…nor when you are in a state of sexual impurity and have not yet taken a bath.} [Quran 4:43].

Menstruation is like ritual impurity in this rule. It is even described in another verse as "harm”. Allah Says (what means): {And they ask you about menstruation. Say, “It is harm, so keep away from wives during menstruation. And do not approach them until they are pure.} [Quran 2:222]

‘A’ishah narrated that the Prophet said: “I do not make the mosque lawful to the Junub (a person who is in the state of ritual impurity) or the menstruating woman”. [Abu Dawood] Imaam Muslim also reported that ‘Aa’ishah narrated that the Prophet said to her: ''Get me the mat from the mosque.” I said: “I am menstruating.” Upon this he remarked: “Your menstruation is not in your hand.”

The evidence is that a menstruating woman should not enter the mosque. But she can enter her hand in the mosque to take something because the hand is not the place of menstruation. The Muslims should try to provide a place next to the mosque for teaching and studying the Quran. This adjacent room is not part of the mosque and the rules of the mosque do not apply to it. So the mosques and Islamic centers should provide such rooms in order to avoid putting Muslim women in an embarrassing situation or making them give up participating in such lessons when they have a legal excuse. (Menstruation)

Allah knows best.