Thanks for writing in.
There is no need to worry. As sex happened after 5 hrs after your period got over, no chance of getting pregnant. Again you took postinor -2 after sex, so that bleeding after 5 days was due to that pill.
Delay in periods and abnormally light bleeding was due to hormonal
interference in your cycle by postinor. As immediately after periods again, you had bleeding after 5 days; you got your periods late.
I hope I have clarified your doubt. Feel free to revert back in case of any doubt.