Unlikely... Hernias directly through the abdominal wall, when you haven't had a surgery or trauma to the area, are very rare. Depending on where it is, a hernia would have to go through several opposing layers of muscle or fascia. Hernias usually develop in natural weak points, like the inguinal or umbilical area. If you have a bulge anywhere on you abdomen and you cannot push it back in, see a doctor.
Spigelian hernias. Agree most hernias are groin (inguinal or femoral), belly button (umbilical), incisional after surgery. Sometimes can be ventral (midline split of rectus abdominus tendon). Can also get hernia along the outer aspect of the rectus muscles (spigelian hernias). Hiatal hernias: internal (stomach pops above the diaphragm)-different. See your doc, get examined. Ct abd wall, while bearing down, may show.