Hello dear, I understand your concern. Iam sorry for your condition. In my opinion the sexual abuse in past is neither going to affect your future pregnancy nor it will prevent the pregnancy. There are various causes for irregular periods like thyroid abnormalities, polycystic ovarian disease (PCOD),high prolactin level, anaemia, overweight, obesity,stress etc. So the above causes should be ruled out by necessary investigations like ultrasound,thyroid profile,HB,serum prolactin etc. Weight reduction in case if you are overweight or obesity will be helpful. So adapt healthy lifestyle like exercise daily and healthy nutritional diet. Avoidance of stress and anxiety regarding pregnancy or any is very much important as they cause hormonal imbalance and cause irregular periods and delay fertility. Don t worry periods become regular once the cause is treated. Also regular intercourse increases the conception chances. Nothing to worry. Hope this helps. Best regards...Dr.Srilatha