Thanks for the query.
According to the description the possibilities are:
-Anemia, if you had mild anemia
previously, the blood loss during periods can exacerbate the symptoms. That can lead to weakness, tiredness
leading to excessive sleep.
-Infection, sometimes infections can decrease the generalized immunity and can lead to excessive tiredness etc. Your gastric symptoms can be because of this.
So if these symptoms continues better to consult physician once and get examined.