Hi, You had early periods because of the tablets you took. And which may also has an effect which leads to less flow. You can count the date of your periods one month after the recent one u got. It can't be confirmed unless you check with the pregnancy test after a well that u a really are pregnant or not. But mostly it was a withdrawal bleeding and u are most likely to be in you next cycle. A word of caution , do not pop up such pills regularly. And if you have to take them , please take them as soon as possible , may be within 12 hours to ensure maximum effectiveness.