The concept that there were Seven Sacraments/Mysteries from the earliest days of Christianity, is false.  Questions over the nature of the humanity and the divinity were discussed for centuries.

Questions over the nature and relationship of the Holy Spirit were also debated [we owe the clear teaching of "three Cappadocians" for that].  

These are major foundational DOGMAS that were still discussed even after the Council of Nicea [325], Council of Constantinople I [381], Council of Ephesus [431] and the Council of Chalcedon [451].   But discussions/controversies still continue in the Christian church about the nature of Jesus Christ---so the Council of Constantinople II [553] and the Council of Constantinople III [680-681] were called.

Sacraments, nor their number were discussed here---because the numbers were not central to our faith.  "The communion of saints' is not necessarily the Holy Eucharist, but the unity/community that were essential to the Faith of Christians.