Did the conversion of Paul occur before or after the Ascension?

According to the Bible, the conversion of Paul occurs when he is walking on the road to Damascus and suddenly has an encounter with the resurrected Jesus. My question is, did this encounter occur before or after the Ascension? The Ascension is where Jesus is said to have ascended bodily into Heaven 40 days after the Resurrection? If it happened after the Ascension, how would it have happened? I thought Christians believe that Jesus won't come back to Earth after the Ascension until the Second Coming. Am I wrong about that? Did Paul just have a vision of Jesus rather than having a physical encounter with Jesus' resurrected body?