Does light bleeding accompanied by pain and continuous in the first month of pregnancy invalidate the fast, and what should she do if it continues or stops?

Since the questioner is in her first month of pregnancy, she must continue her fasting and prayers, and pay no attention to the blood she sees, as it cannot be menstrual blood because a pregnant woman does not menstruate. Nor is it post-natal bleeding, because the minimum period for the formation of a fetus is usually 81 days. Therefore, the blood is irregular vaginal bleeding (istihada).