Is my lower right sided pelvic pain due to osteoarthritis of lower back

It may be: But get checked by your gyn. It could be in the pelvis. One good medicine for arthritis pain is Cymbalta (duloxetine) if u are not on that. It builds up transmitters in the brain that decrease ascending pain signals. Make sure you get good sleep at night and don't clinch or grind teeth a lot at night. You could have a UTI though, they come up atypically at times. Good luck.

Possible: Would recommend seeing a spine specialist to evaluate the facet joints as source of pain.