Thanks for writing to DoctorSpring.com with your health concern.
From the encounter you describe, pregnancy is least likely.
She cannot be pregnant from just touching.
If you are not reasonably sure of the exchange of seminal fluid, then go ahead and take the Plan B ( it can be taken upto 120 hours after unprotected sex ).
Plus , pregnancy within the week when the period just got over, is again less likely.
Just to be sure, a test can be taken 2 weeks after unprotected sex.
All the best
Take care, and please feel free to discuss.