Temporary Unaccompanied Minor Fostering with bio 15 month old and possible pregnancy?

Hi, My husband and I have an opportunity to foster unaccompanied minors for 2-60 days while they wait to be reunited with a family member. There's a year-long commitment, so we would likely have multiple kids come through over time. We would also be dropping them off Monday through Friday from 8-5 at a church for wraparound services--therapy, medical help, etc. We would love to help and share our good fortune. At the same time, we have never fostered, have a 15 month old son, and are currently trying to get pregnant again. Any thoughts on whether this would be wise in light of our current situation? I've read a bit about birth order being important, but the kids we would foster would be 2-12, so older than our son. Any input would be appreciated. Thank you!