Hi, Thanks for writing to HCM . Yes irregular cycles cause infertility. So I suggest you following investigations to know the cause of irregular cycles and take treatment accordingly. -- thyroid profile, serum prolactin, ultrasound abdomen to rule out polycystic ovary disease (pcos). The pain in breast during cycles is seen in some people. Don t worry for that. You can take primrose tablet after consulting your doctor and pain killer. Normally breast develop in proportionate to body . If you still feel your breasts are small compared to your body then for external appearance you can ware thick padded bra. For your sexual life, then you can go for breast enlargement surgery by a plastic surgeon. Hope I have been helpful . Regards Dr.Deepika Patil