As mentioned you had unprotected sex 6th day of your menstrual cycle which was during safe period so chances of pregnancy
is least.You took levonorgestral tablet which has a side effect of spotting, abdominal cramps , nausea vomiting
which generally resolves as its own ( if more symptomatic then take anti spasmodic sos , pantoprazole
twice a day for 5 days).
If you are amenorrhoea persists( as forgot to mention) following that sexual contact even after one week of expected date of menstruation
then do UPT to confirm pregnancy status and if it comes negative n amenorrhoea persists then visit gyne clinic for clinical evaluation n investigation including TVU and treated accordingly.
Hope this ll help
THANKS N REGARDS
So don't worry