Can I have endometriosis without having any symptoms?

Yes. We think that about 20% of the pt with endomtriosis are asymptomatic.
Unlikely. But no way to know to start investigating unless you start presenting with symptoms that would make a gynecologist suspicious. Prevalence of endometriosis is influenced by the population being studied. 1% of patients undergoing any gynecologic surgery had endometriosis upon inspection of pelvic cavity. Speak with gynecologist about any specific concerns related to your medical history.