There is always a chance of pregnancy. Precum is considered not to contain sperm if you have not recently ejaculated - as in since the last time you urinated.
If you hadn't recently ejaculated and pulled out in time then it's unlikely.
The good news, if she expect her period within the week then it is VERY unlikely she'd get pregnant anyways. The timing is poor. She's at her lowest fertility. Normally she'd ovulate between days 11 and 16 of her cycle, day 1 is when her period starts. 48 hours after ovulation the egg isn't viable. Since you say "within the week" she's about day 21 or so of her cycle.
Hope it helps.