Congratulations on your conversion and on receiving the sacraments. I myself am a convert from the Jehovah’s Witnesses, and have grown so much in my three years as a Catholic. It was not a sin for you, before becoming Catholic, to have recieved Communion in a Protestant church. Protestant churches do not have valid priestly orders, so they have no power to achieve the transubstantiation of bread and wine into the Body and Blood of Christ. Therefore you did not receive unworthily. Furthermore, every mainline Protestant church has long since rejected as archaic the sacrifice of the altar. It is for this reason that the preacher at a lectern with the Bible is the focus of their services, and when they do have an “altar” it is really just a common table and they only claim that their “sacrifice” is symbolic. However, if you ever received a Protestant communion after full knowledge and acceptance of the Catholic doctrine concerning the sacrifice of the Eucharist, that is something you should include in your first confession. Again, congratulations and welcome to the One Holy Catholic and Apostolic Church.
