I need help!

My first day of period last month was 2nd of July. I had unprotected sex on the 10th of July, and my bf ejaculated inside me.
I took the first postinor-2 pill in less than 2 hours after the unprotected sex and then the 2nd pill 12 hours after taking the first pill.

On the 13th of July which is 3 days after taking the pills, i had blood discharge which was dark colored and different from my usual period. It lasted only for 3-4 days. Is this considered as my period?


It is now the 38th day of my menstrual cycle if i count from 2nd of july.
Or am i supposed to start counting from 13th of july which i experienced the blood discharge?



I am super confused. When is my next period supposed to come?
I usually have 29-31 days menstrual cycle but my previous period (July) came on the 36th day.


I am confusedddd!!~~~