Use one of those home ovulation test kits. They sell them near the pregnancy tests.
It will tell you when you are most fertile. Then, have sex like crazy during the 2 days before and after that time

yep...once you know when and if you ovulate you can go from there. Periods arent alway the best way to tell....

Good luck..theres a lot of great information in the GETTING PREGNANT forum. They helped me conceive...im now 6 months preggos

You should also try tracking your fertile days, this way you can recognize some sort of pattern to it all a few months down the line.

I would go to a good herbalist doctor to give you herbs to help you regulate your period. I have read a lot about how herbs like Vitex and Don Quai help women regulate cycles to ttc.