Quick credit risk question for forwards question, positive, position, long

smartpants

So before expiration, is the value to the long position just
Spot / 1+Rf foreign ^ n
minus
Forward / 1 + Rf Domestic ^ n
If this value is positive then the long faces credit risk?
At expiration, is the formula just
Spot - Forward, and if it is positive then long faces risk?
This subject is going to be the death of me in 2 days