Thank you for the query.
First of all an explanation for you. Appendicitis
can not be ruled out by ultrasound. Especially if the doctor who has performed the ultrasound didn't find the appendix. It simply means that your appendix could not be found with ultrasound. So if it was not found, it`s inflammation cannot be ruled out. Moreover about 50% of appendicitis is treated with antibiotics with very good response. But such inflammation can recur. So it is possible that you have the appendicitis again. This should be checked as soon as possible. So you should have abdominal ultrasound and fool blood work, liver and pancreas tests, urine analysis.
Such symptoms can be also caused by mentioned by you uti or kidney stones, ovarian inflammation
, ovarian cyst
rupture, pregnancy or even endometriosis
. It is strongly advisable for you to visit gynecologist and have transvaginal ultrasound
Hope this will help.