Hello dear
I understand your concern
You got period on 2nd july. Did sex on 13th july.
If you have regular period of 28 to 30 days then 10th to 18th day of period considered as fertile period.
So there is high chance of
pregnancy as you did sex on 11th day of period.
You can take
I pill as early as possible with in 72 hours of sex to prevent unwanted pregnancy.
If 72 hours has been crossed then wait for period to come.
If period will delay by more than 7 days form your normal expected period date then go for urine pregnancy test and or blood
HCG test to confirm pregnancy.
Avoid
stress, take healthy diet, drink plenty of water, maintain proper pelvic hygiene and do regular exercise.
Hope this may help you
Contact further if follow up needed
Best regards
Dr. Sagar