Hi ! The pain in the right side of lower abdomen could mean many common pathology :
1) With the urinary symptoms, it could be a
urinary tract infection or a right ureteric calculi. Go for a routine urine test and an
ultrasound KUB to exclude these after getting consulted by your treating physician. However, this could also be due to any recent increase in the water intake as told by you.
2) Next common pathology which comes to mind is a attack of mild sub
acute appendicitis. This may be with/without any
nausea feeling and initially starting at para umbilical region about which there is no mention. Also
appendix can irritate ureter/bladder depending on its position, and give rise to urinary symptoms mentioned by you. One has to give it due importance as leaving a diseased appendix could be hazardous than removing a normal appendix. To exclude this you will have to get clinically examined by a surgeon and also get investigated as advised by him like routine blood tests and may be an ultrasound to exclude other conditions mimicking appendicitis.
3) More common condition is a
colitis and for this you can get your stool tested for ova and cyst and get treated accordingly.
4) You have not mentioned to which sex you belong to. In case of females, apart from the causes mentioned above in 1-3, one has to exclude some conditions specific to ladies, like pelvic inflammatory diseases, an unruptured or sealed ectopic
pregnancy, etc.
5) To think of some remote possiblilities, some pathological process in upper abdomen can also give rise to pain in the lower abdomen.
Therefore , I will strongly recommend you to get yourself examined by a surgeon/gynaecologist if female. Wishing you a an early recovery.