I have a big chocolate cyst in my left ovary and don't want surgery as i had one already for uterine fibroids, can i be pregnant with it?

Possible, not likely: I would recommend removing the endometrioma if you hope to conceive. Its effects are not just destructive to the ovary involved but also deleterious to the entire pelvis and both tubes - which could seriously decrease your fertility. Seek care with a reputable infertility specialist or laparoscopic gynecologist to address this at your earliest convenienc. Take Folic Acid 1-5 mg daile and good luck.