First, I’m so excited about your journey. I will keep you in prayer today!
Secondly, coming from a Protestant background, you cannot be a “catechumen” (a label reserved for non-Christians entering the Catholic faith); you would be considered a “candidate.” At your confirmation, the priest will formally welcome you into the communion of the Church, at which point you truly shall be “Catholic.”
That being said, it may be appropriate in certain circumstances to refer to yourself as Catholic before you have been received into the Church. Your beliefs are certainly Catholic, you are in the process of entering the Church, and you are already spiritually united with the Church in baptism. I found it easier to say “Catholic” if someone asked me my religion on the fly, even before I was fully confirmed, and when describing the technicalities of my situation was unnecessary.
Of course, saying briefly that you are “entering the Catholic Church” whenever someone asks you your religion is an excellent way to witness. People ALWAYS react to that statement–positively, negatively, or with curiosity (voiced or not).
I avoided that explanation in circumstances when I realized stating my actual situation would ONLY raise alarm and hostility; at those moments (i.e., in fundamentalist environments), I preferred to humbly say I was “Catholic.” People treated me kindly then, as if I was their new evangelistic mission field. I was assured of some measure of openness and kindness. By contrast, when I described my situation in those environments, I was IMMEDIATELY harassed or silently scorned. This happened so many times in the Christian college I attended, it just seemed better not to explain unless I felt I could trust my listener (which didn’t always prove to be the case).
I guess my central advice is this: if it is your firm and irrevocable desire to enter the Church, and you have already begun to attend RCIA, feel free to apply the label “Catholic” to yourself in a loose sense when appropriate. I am open to correction on this, but I don’t believe that any Church law would object to that usage. I certainly never doubted myself when I used it.
