How your endometriosis was diagnosed was not indicated. Endometriosis is usually detected with an ultrasound but it can be proven only with a laparoscopy with biopsy which is the only secure method.
Pain during the menstruation (dysmenorrhea) is the most common symptom of endometriosis. Pain, during and after sex, is also possible, but not so common as dysmenorrhea.
You should consult your gynecologist about this.