Smelling fish randomly?

Idk what's wrong with me but lately i smell fish out of nowhere. It's not in a particular area but it happened three times today, twice at work and once in my bathroom at home. (It's not me, it was before I used the bathroom when I just walked in.) I had to remove myself and walk somewhere else while at work because the smell was so strong. But then the smell will go away and I will smell it again later. I looked it up and apparently there could be something wrong with me like a tumor. Is this serious enough to get it checked out? I've asked people to smell things because i feel like I'm going crazy and no one else smells it. It's really hard to deal with because i feel crazy.