This wasn't communion. "Breaking bread" was and is a common term in King James time for eating a meal together.
In addition, this occurred on a Saturday night, not a Sunday. The phrase translated "first day of the week" is literally the "first of the sabbaths" or perhaps the "first sabbath". It could indicate the first of the sabbaths counted toward Pentecost between the days of unleavened bread or simply denote that they met on the sabbath. At any rate, when the sun went down on Saturday, a new "day" began. This was a meal, a potluck if you will, that they were eating together.
1Co 16:1 - 2 Now concerning the collections that are made for the saints: as I have given order to the churches of Galatia, so do ye also. On the first day of the week, let every one of you put apart with himself, laying up what it shall well please him: that when I come, the collections be not then to be made.
This is a one time occurrence. A special collection take up probably for the saints in Jerusalem as referenced here:
Rom 15:26 For Macedonia and Achaia thought it good to make certain gifts to the poor of the saints in Jerusalem.
It doesn't say that they gathered together, only that they individually were supposed to gather together foodstuffs, supplies and whatnot so it would be ready when Paul arrived.
If you want to use scripture as an example of believers gathering together, then the overwhelming NT evidence is that they gathered on the sabbath day:
(Act 13:14) But when they departed from Perga, they came to Antioch in Pisidia, and went into the synagogue on the sabbath day, and sat down.
(Act 13:27) For they that dwell at Jerusalem, and their rulers, because they knew him not, nor yet the voices of the prophets which are read every sabbath day, they have fulfilled them in condemning him.
(Act 13:42) And when the Jews were gone out of the synagogue, the Gentiles besought that these words might be preached to them the next sabbath.
(Act 13:44) And the next sabbath day came almost the whole city together to hear the word of God.
(Act 15:21) For Moses of old time hath in every city them that preach him, being read in the synagogues every sabbath day.
(Act 16:13) And on the sabbath we went out of the city by a river side, where prayer was wont to be made; and we sat down, and spake unto the women which resorted thither.
(Act 17:2) And Paul, as his manner was, went in unto them, and three sabbath days reasoned with them out of the Scriptures,
(Act 18:4) And he reasoned in the synagogue every sabbath, and persuaded the Jews and the Greeks.
Not to mention the example set by our Lord himself. "Christians" are those who follow Christ, imitate him. Paul said:
1Co 11:1 Be imitators of me, just as I also am of Christ.(NASB)
Paul kept the sabbath, Christ kept the sabbath. It's a commandment of the Lord, one of the ten commandments.
So it is your position that the empty tomb was discovered on a Saturday, rather than the generally accepted Sunday at daybreak? That would have to be your interpretation of Luke 24:1, where the same set of words is used as is found in the passage in Acts.
This was a meal, a potluck if you will, that they were eating together.
The bread which we break, is it not the communion of the body of Christ? 1Cor 10:16
And I find your interpretation of the meaning of the 'first of the week' to be a bit strained.
Are you a follower of William Miller?