Render Problems

I am VERY new to 3D modeling and Blender. I am working on my second project now and have run into a problem with rendering. I have created everything and have rendered plenty of times up until now. I just finished adding some particles to my model, and now when I render nothing shows. I only get a blank gray screen. I can see everything just fine through my camera view, so I know it isn’t that. Anyone have any suggestions?

Not sure without the Blend file to look at, so if you could attach that somehow, it would help a lot. As a note, this should be moved to the lighting and rendering section.