When can you call yourself a physicist?

I'm currently a student pursuing a physics bachelors degree. According to some definitions, if you've had a professor cite from your research papers, you can call yourself a physicist. I've already accomplished that (published a research paper, which was cited by my mentoring professor), but I feel only someone so arrogant would give themselves that title so early. Others say that you can never call yourself a physicist unless you are recognized for distinct contributions of yours, while others say that you receive title once you complete a phD and a post-doc. Since it is not a regulated profession, how would one know when it is appropriate to call themselves a physicist?