Most of the things that could hurt on the upper left side are not related to sex but to eating and are gastrointestinal in nature. When not related to sex, it could be your stomach and your pancreas. Gallbladder infection or gallstones may also hurt in the upper part but none of these disorders are sex related.
I can’t pinpoint this pain to having sex. If sex hurts and it shouldn’t (ever), it may hurt in the lower abdomen or in the vaginal or vulval area.
This is what I know but I am not a doctor and you better see a doctor on this topic. Only a thorough examination and your additional symptoms and medical history could point a finger or tell what the problem may be.
Information on this site is provided for informational purposes only.
It is not meant to substitute for medical advice provided by your physician or other medical professional.
If you have or suspect that you have a medical problem, promptly contact your physician or health care provider.