Hi jlatino,
Let me try to give you a simple straight-forward answer : Your chemical and hormonal balance of your body is "out of whack". Yes, you could have deficiencies, stress, etc. but it all comes back to maintaining proper body chemistry, so your hormones levels are where they should be for optimum health. I am very big on natural remedies, although, as most seem to always suggest visiting your physician (doctors can be great, but ultimately nothing beats knowing your body and learning to care for yourself to prevent illnesses and disease in the first place.). In our western world...doctors treat symptoms not the root problem itself. I know it can be tiring to hear, but I always recommend taking a high quality multi-vitamin that will help to balance your body back out and, if needed, try a NATURAL remedy first. You can always go to the doctor later and let them barrage you with tests only to hear them tell you you may have low iron levels or something along those lines.
I included a link to 2 of the best multi-vitamins available. Try them for one month and get back to me. Either will help with repairing your cells and correcting hormonal problems.
Xtend-Life Total Balance or Micro-Nutra Vita-Female
If you need an additional natural remedy, I also included a link to one my friend uses to alleviate and regulate her cycle.
Xtend-Life Female Rejuvenator
Live well, be healthy - jlatino!