Prophesying has two-fold meanings, while foretelling is no longer a sole gift of the true prophets.
Acts 2:17-18 (NIV):
In the last days, God says, I will pour out my Spirit on all people. Your sons and daughters will prophesy, your young men will see visions, your old men will dream dreams. Even on my servants, both men and women, I will pour out my Spirit in those days, and they will prophesy.
Anyone may be given the gift of foretelling.
While prophesying is not necessarily fore-telling. It is more on Paul's way of ministering.
1 Corinthians 14:4 (NRSV):
Those who speak in a tongue build up themselves, but those who prophesy build up the church.
However either way, it's not a sole gift of the prophets. A prophet is an eyewitness of God who bear witnesses for God. Basically he can communicate with God in a prophet's unique way. Paul, though ranked as an apostle, falls to this category.
Some characteristics of a standard NT prophet:
Jesus/God shows up in a supernatural event, and identified Himself to the chosen prophet (though Paul ranked as an apostle),
Acts 9:4-5 (NIV):
He fell to the ground and heard a voice say to him, “Saul, Saul, why do you persecute me?”
“Who are you, Lord?” Saul asked. “I am Jesus, whom you are persecuting,” he replied.
Jesus/God confirms His own message by enabling the prophet to perform miracles. He authenticates both the prophet and the message he carries by enabling him to perform miracles and possibly fore-telling (a form of prophesying),
Acts 14:3 (NIV):
So Paul and Barnabas spent considerable time there, speaking boldly for the Lord, who confirmed the message of his grace by enabling them to perform signs and wonders.