Pain in lower abdomen. On one side!

Mild Pain in lower abdominal(pelvic region)..earlier when i used to stand up after long sitting i used to get a feeling of something stretching in both sides of the pelvic region which was slightly painful for 1 min approx and then it used to be fine...after quarantine since i am a student  (MBBS )i sit for longer duration to study and now the pain has become more frequent..and i feel heavy after having a full meal..i also had a feeling of pain month back in right upper abdomen for which i went to hospital and they suggested usg which came out to be normal..and i also sometimes feel lymph nodal enlargement in my neck region...and also mild submandibular glandular enlargement not properly but slightly (my friend who used to sit with me in college developed mumps 6 months  back but i already had mumps when i was a child so i thought i am immune to it ) ..also my jaw makes clicking sound on one side!!