That's not good
There was no signed contract. Basically the magazine companied just told me that I got an intern so I started working for them. So there's nothing I can do? It's just not fair for them using my photos and not putting my names on it.
Generally, any work you create when working for an employer that falls within the scope of your employment belongs to your employer. These works are considered works made for hire for the purposes of the Copyright Act.
An employment relationship must exist for the work for hire rule to apply unless there is a written and signed work for hire agreement.
A work for hire agreement that is NOT part of an employment relationship will only cover works in 9 different categories. These categories are outlined in the US Copyright Act (17 USC section 101):
https://www.law.cornell.edu/uscode/text/17/101.
There are several factors looked at by courts when determining who owns the copyrights in an employment situation. I can go through these factors if you want me to, but it appears from what you have said that the copyrights in the works you created when with the magazine belong to the magazine.
The copyrights in works created outside employment settings, with a few exceptions, belong to the creator of the work. For these works, the copyright holder must sign a written transfer of rights agreement to change ownership of the copyrighted works.
You could approach the magazine publisher/editor and ask about copyright ownership and, if owned by the magazine as I suspect they are, you could request that all works you created for them are credited to you. Many if not most publications will credit their creative STAFF somewhere, if not always on the work itself. Policies vary on interns, though.