is it bad that sometimes i feel nothing?

I wouldn't say it is good, nor bad. I experience that same feeling a lot lately. I guess it's triggered due to something from the past. That's all to it.

The fact that you worry that you are emotionless indicates SOME level of feeling. A completely empty person wouldn't care. Explore what you are thinking, or worrying about, or even what you think you SHOULD be feeling when you encounter this.... it may help you to discover a core issue.

I would call it a neutral feeling because I feel like this when I'm not around anyone and by myself. If you're around someone, try to engage in conversation more.