Dear Isabella,
Irregular menstrual cycles are not uncommon. Using the BCP replaces the natural ovarian hormones with artificial ones which lead you to think your cycles are better. They are not — only regular. When you stop using the BCP you most likely will return to having irregular cycles again. This may or may not effect your ability to become pregnant. We do know that the artificial hormones which stop the natural occurrence of a healthy cycle can make it difficult for some women to achieve pregnancy easily.
In place of the pill I suggest that you take a course in natural family planning so that you will begin to understand how your body works naturally without the very significant interference of BCPs. Any irregularities in your menstrual cycle can then be addressed on that basis, instead of just covering them up with the pill. Treating your body well with moderate exercise, a healthy diet, and applying natural family planning principles will go a long way toward making you fit for love and life. Your chances of getting pregnant later on will definitely be enhanced.
Best Wishes, Carol