Sorry, I forgot to mention, your doctor will give you the appropriate medication for you if you let him know you want to conceive. They do have medication that helps with ovulation. Good luck.
Hmm, make an appointment with your doctor. There's always a chance you might have Polycystic Ovarian Syndrome and that might explain your irregular periods. Request an ultrasound, perhaps to rule out cysts. Stress can also affect your cycles. Could be a number of things affecting it. Seek medical help. Good luck.