Smelling Ammonia after a run

Hi all.

I recently started training for a half-marathon. Don’t have any running experience and ran my first 10k today.

The run itself went really well, i was feeling really good, but when i got back indoors for a few minutes all i could smell was a strong scent of ammonia. I think it was actually coming from my body somehow.

Anybody know what this could be? Should i be concerned? I don’t have any health issues that i’m currently aware of. I consider myself healthy as i have quite an active job. I’m a 21 year old male.

Thanks!