Is it obligatory to make up the day on which I anticipated the onset of menstruation before the Adhan, and then confirmed the discharge of a brownish discharge and a small amount of blood a while after the Adhan?

The presence of signs of menstruation is not considered menstruation unless the blood itself flows. Therefore, if blood does not flow before sunset, the day on which these signs appeared does not need to be made up. It is also advised to be wary of obsessive thoughts regarding purity, prayer, and other matters, by seeking refuge in Allah from them and disregarding them.