Re: Hernia or pulled muscle?
Probably just a pulled muscle, but yes, you can get a hernia as quickly as you can pull a muscle. The only way to tell for sure is to get checked by a doctor. If it doesn't start getting better after some time, it could be a hernia. Hernias do not heal without surgery.
You can get a hernia anywhere along the abdomen wall, or anywhere there is any kind of "wall" really, but for us guys, they are more common in the left and right groin area (aka inguinal hernia) due to the reproductive tubes that pass through the abdomen wall. They create a weak point of sorts. I had one repaired a couple years ago.
Again, only true way to tell, is to see a doctor. Or in my case, wait a year until it becomes very obvious what it is. I would say if you aren't starting to feel some kind of relief in a few days, definitely see a doctor.