Is it normal that i feel a stab when i have fantasies?

Whenever I think about attractive guys kissing me, getting hurt(random fetish I have) or any other fantasy, I feel a stab in my stomach for a few seconds. It really hurts and sometimes it even takes my out of my thought. I usually like it because pain sort of turns me on, but I don't think a normal person would enjoy it.

I used to think it was some sort of extreme "butterflies in my stomach" sort of thing, but It's not. I only get this pain when I think about something arousing or attractive.

I would just like to know if someone else feels this too. I'm deeply sorry for any grammatical errors I made. English is not my native language.