Pictures on my D7100 come out dark. Any

I have nikon D7100 and i shoot manual. I know how to shoot manual. Everytime i take a picture it comes out a little dark and i always have to fix my exposure compensation.

It sounds like you're making the mistakes, not the camera. If you really know how to shoot manual that's great but also understanding that lighting conditions change every time you move the camera is also important.

So here's something that may help. Use your camera in the "P" mode (program). Half press on a subject, any subject and look at the camera's settings for light - those being shutter speed, aperture and ISO. Would you have set it the same way? Or would you opt for changes that may make the shot dark? It's a way to see whether or not you're being accurate with your settings.

Try shooting in Aperture Priority, with the aperture at the widest
If you get the exposure right, check out the EXIF info - so know the settings
Maybe even step up the ISO if need be

I'm still learning with every shot

I feel awkward telling you to brush up on the 'exposure triangle', given your expertise on manual exposure
Goodluck

For once, I agree with JimA completely. Check the camera's thoughts about your exposure compared to what you think should be proper exposure. I think you will find that the settings are going to be different.

The meter in your camera works in manual mode, check your manual on how to use it. Even if you don't want to bother with switching to P and back, the meter on the camera will tell you if your exposure choices are close or not.

Don't use exposure compensation unless there's an actual need to do so…