lump on left groin

Hi,

I'm a 24 year old male. This incident happened way back then but i just need some answers. I remembered sitting on chair and lifting 10 lbs dumbbells on the chair (i know stupid right?). And then, shortly after that, i noticed a small, probably pea sized lump on the left side of my groin. It was totally painless unless i pressed it reaaally hard. And then it went away just like that. I didn't feel sick or anything. No fever, headache, etc..

So my question is, was the lump related to some viral illness or was it hernia? But as far as i'm concerned, hernia tends to stay and not go away suddenly right? Was it just a muscle strain?
Thanks.