Is the fast of one who, having bathed after menstruation in Ramadan, later doubted her purity, considered valid, knowing that she only broke her fast for 11 days in Ramadan and used to take a few hours to ensure purity?

If a menstruating woman confirms her purity, she performs ghusl (ritual bath) and is not required to wait, as Ibn Abbas said: "As for what she saw as purity for an hour, she should perform ghusl." What happened to you after months of doubting your previous purity should not be heeded; it is from the whispers of Satan.