Actually, you will formally become a “candidate” for reception into full communion with the Church, not a “catechumen,” because you are already baptized.
Having said that, you might let your pastor know that if anything happens to you, you absolutely want to be considered a candidate for entrance into the Church for the purposes of receiving last rites and a Church funeral. You can also carry a card in your wallet that says, something like, “I am Catholic. In the case of a serious illness or injury, please call a priest immediately.” If you formally say, “It is my intention to be received into the Church, as soon as the Church will have me,” then it removes all doubt if the question comes up and you can’t answer for yourself. Also let family members or anyone with medical power of attorney what your wishes are. You already have certain rights as a member of the baptized, but making your wishes explicitly known will help make it certain that someone will think to call a priest for the anointing of the sick, if you are in need of it and cannot ask for it yourself.