Will This Go Away Soon?

im 16 years old . im a girl. and im over weight . so ive been going to the gym these days to lose weight. so i do set ups. but today i woke up in the morning feeling the pain after the exersise which is norman. but therz this vertical like in the middle under my chest. and i really dont like it .. what is it . and will it go away if i exersise more? coz maybe its just the line between the fat under my chest right?