Hello,
Thanks for your query at DoctorSpring.com
I understand your concern
Unfortunately, you took it a week after your period finished, that means you took it too late in the cycle, it should be started while you are on the period.
Also you took it for just 4 days before having sex, so yes, there is a risk for pregnancy.
You could take the emergency contraceptive morning-after pill just to make sure.
All the best
Please feel free to discuss further.
Regards