Can i get pregnant having irregular periods all my life till they just stopped?

i haven't had a normal period since i first started when i was 13, and i only had 2 regular periods then. i am 27 now and i haven't had a period in about 6 or 7 years. i am not on any medication or birth control. i have been to the doctors and they all say the same thing..working diagnosis. i have a lot of health problems, my body is retaining water and my nipples are lactating (not milk) but like before you produce milk. so i guess i'm wondering if my body already thinks i'm pregnant? there for i'm not producing an egg. i'm all kind of messed up but can anyone give me some kind of advice? thank you crystal