Without a clip it will be hard to determine what the issue is. It is either reverb or an actual echo which is unlikely.
It is most likely reverb from the environment, when you speak the sound waves bounce off the desk, walls, monitor and make their way back into the mic. Completely normal.
How close is the mic to your mouth?
Many people make the mistake of buying a nice mic then placing it on their desk 3 feet away from the source(their mouth). A condenser mic you can get away with it maybe about 1 foot, a dynamic is going need to be half that distance or less.
No matter the type of mic, the closer to your mouth you can get it(within reason), the better it will sound and reflections become less noticeable because your voice it taking up most of the frequency spectrum. You can then use an expander VST to take care of the tail of the reverb that is left over when you stop speaking.
