Thanks for posting your query.
With the available described symptoms, there appears to be possibility of hernia
with tear in rectus abdominal muscles.
Presence of something bulging along with little sore suggests the diagnosis.
You should consult with internal medicine specialist/ general surgeon
and should go for thorough check up.
You should also go for ultrasound
imaging for better clarification.
If hernia is diagnosed, then you should go for tear correction and should wear LS belt for strengthening abdominal muscles.
You should avoid weight lifting for coming few days.
Dr. Mayank Bhargava