What Could Be Causing My Upset Stomach After Taking Gynecosid For Missed Periods?

Hi, the last time I saw my period was on the first of march to 5th of march after than till now I didn t see my period. I visit my doctor I was ask to take gynaecosid which I took on the 21 and 22 of April throughout on the 23 of April I have been having stomach upset. Please what causes