There may be various causes for pain abdomen.You have not mentioned other symptoms associated with stomach ache like vomiting, any bowel or urinary problem.
Swelling of liver associated with fever may be due to hepatitis
or just a nonspecific coincidental finding. Hepatitis is usually accompanied with jaundice
and raised liver enzymes.
Urinary tract infection
can also cause severe pain
abdomen and fever.
So I will recommend you to continue the antibiotic treatment for UTI and get a liver function test done. If LFT is deranged then it will suggest hepatitis otherwise this swelling is nonspecific and will subside on its own.