Is it a hernia or a groin pull?

Basically around 7 months ago in March I went to the doctor because I had something that felt like a ball in my groin on right upper side of my pelvis, It did hurt for a few days and was painful but back then I was playing football and going to gym 3 times a week, i went to the doctor and he said it was just a muscle strain and it would go away and gave me painkillers, the ball never went away in my pelvis but the pain was gone and i don't even feel the ball only when im laying down all the way or arch my back, Now that im starting to get back into the habit of going to the gym and playing football its causing me some soreness but I can't tell if that soreness is from just being inactive for so long - or from the strain or possibly hernia thing