Welcome to HCM.
If a woman came to my clinic with similar complaints the possibilities are
1. an ovarian pathology probably an ovarian cyst
that causes imbalance in hormones with pain. For this you need an Ultrasound
3. An ectopic pregnancy, where despite tubal ligation
the pregnancy occurs, sometimes in places outside the uterus [like the tubes]. To rule this out a pregnancy test is helpful and if it is positive you need to see your gynec urgently as it is a surgical emergency.
2. another possibility is gastroenteritis
where there is an infection of the stomach, intestines or appendix. Gastroenteritis is associated with loose stools and vomiting. Most of the time this is self remitting and simple measure like a light diet like soups, low in oil help along with probiotic foods like yogurt to help restore the normal intestinal bacteria. If it is not controlled with this you will need to see your physician.
I suggest that you take a pregnancy test and if it is negative then no need to worry, eat simple food with probiotics and wait.
Hope I was able to help you.
Thanks for the query!