Is it normal that i have a weird feeling in my gut for no reason?

I'm sorry I'm not able to describe this better, but...

I have this weird feeling in my gut/core. This sensation is paired with a constant fast/hard beating of my heart. I also slightly shake.

I'm not always like this, but it's been occurring more often as of late.

I'll feel silly if these are symptoms for something obvious, but I honestly don't have a clue and I don't want to deal with it anymore. It makes me feel so weird.

(And no, It's not love like other people I've asked have told me.)

I'm sure it's nothing serious, maybe an imbalance of chemicals? I just want to get an idea of what it might be; a lead. To find out if I should be concerned/consult a doctor.

Is this feeling normal? Do you also feel this way sometimes?