So I’m 15 and I woke up with some stomach pain, this led to testicular pain. I decided to check it

This is difficult to say, the typical symptoms for testicular cancer are these:
-A lump in either testicle; the lump typically is pea-sized, but sometimes it might be as big as a marble or even an egg.
-Any enlargement of a testicle
-A significant shrinking of a testicle
-A change in the consistency of a testicle (hardness)
-A feeling of heaviness in the scrotum
-A dull ache in the lower abdomen or in the groin
-A sudden collection of fluid in the scrotum
-Pain or discomfort in a testicle or in the scrotum
-Enlargement or tenderness of the breasts.
You should really get the lump checked out by your doctor, please don't be shy, just go to be sure.