A few years ago I worked in a lab as a visiting researcher (something like internship). As the result, I had to write a short report which at that moment didn't look like a proper paper. Recently I've discovered that my supervisor literally 3 months after my leave decided to present a conference paper with the results of, well, our work (at least I think that these two documents contain the same idea).
I do prefer to keep my old works and emails so that I can always check and find something. It seems that I sent a copy to my supervisor and the paper was submitted approximately one month later.
Since it's not so common, I've asked my former supervisor already and I've got a reply "What are you talking about?". Now I'm confused and feel a bit stupid because I might be wrong as well.
I've checked related questions: Is it plagiarism for my thesis advisor to publish a paper using content from my thesis without citation? What should I do if my master's advisor used a figure from my thesis in a publication without citation or acknowledgment? and I need to clarify my problem a bit. The idea of the project came from my supervisor, I was needed as a person to read a lot of papers and to do a lot of routine calculations (6 months(!)).
Is there anything I can do now? It's not like I care now about a conference paper, however, at that moment I was looking for a PhD position and all professors kept asking me about my publications and results of my internship. And I've sent that letter already.