Hi there.Delayed periods could be because of many causes like Significant weight gain or loss,Overexercise,Poor nutrition, anemia, hypothyroidism, Smoking,Eating disorders like anorexia nervosa,Increased stress, Polycystic ovarian syndrome. You have irregular periods because of hypothyroidism. That cyst you have mentioned about is small one and usually they are functional cysts. They resolve in few months without any treatment. If you wanna conceive then have regular sex specially the middle 2 weeks of your menstrual cycle you wil be fertile and release ovum(egg) . If your trying already from one year and stil it dint work then consult gynecologist nearby. Or infertility specialist in your city. IUI ie intra uterine insemination is better for you as you had one ectopic pregnancy and chances of another ectopic is high.