What Are The Side Effects Of Meprate 10mg Tablet?

had unprotected sex on january 13th and got my period regularly twice after that...once in late jan and the next time in february...however, i did not get my period in march..i went to the doctor and she advised me to take meprate tablets 10 mg for three days and i experienced very light bleeding that stopped a day after i stopped taking the tablets..i did a home pregnancy test and it gave me a negative..what could this be?