Are you sure?...
38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost....
16 (For as yet he was fallen upon none of them: only they were baptized in the name of the Lord Jesus.)...
38 And he commanded the chariot to stand still: and they went down both into the water, both Philip and the eunuch; and he baptized him....
48 And he commanded them to be baptized in the name of the Lord. Then prayed they him to tarry certain days...
5 When they heard this, they were baptized in the name of the Lord Jesus.
Paul was baptized, to "wash away your sins, calling upon the Name of the Lord", such a beautiful picture of repentance and salvation as Paul repudiates his former way of life, to trust in Jesus Christ.
Then Jesus taught Paul the Gospel, which Paul went on to teach to us.
Our baptism is spiritual,
Romans 6:3-7 KJV
3) Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death?
4) Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.
5) For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection:
6) Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin.
7) For he that is dead is freed from sin.
We are immersed into Christ, to join Him in His death, burial, and resurrection. Water doesn't do that, the Holy Spirit does that.
Paul affirms this is the only baptism,
Ephesians 4:4-6 KJV
4) There is one body, and one Spirit, even as ye are called in one hope of your calling;
5) One Lord, one faith, one baptism,
6) One God and Father of all, who is above all, and through all, and in you all.
Paul shows this in his practice,
1 Corinthians 1:13-18 KJV
13) Is Christ divided? was Paul crucified for you? or were ye baptized in the name of Paul?
14) I thank God that I baptized none of you, but Crispus and Gaius;
15) Lest any should say that I had baptized in mine own name.
16) And I baptized also the household of Stephanas: besides, I know not whether I baptized any other.
17) For Christ sent me not to baptize, but to preach the gospel: not with wisdom of words, lest the cross of Christ should be made of none effect.
18) For the preaching of the cross is to them that perish foolishness; but unto us which are saved it is the power of God.
He was glad to not have baptized these others, actually thanking God for putting a cap on it! Because Paul's mission was to preach the Gospel in the cross of Christ, which is itself - the cross of Christ - the power of God, not water. Paul wanted nothing that would detract from the cross.
Much love!