What Causes Difficulty In Conceiving When Having Scanty Menstruation?

Hi me and my partner have been trying to conceive with a donor for the past 14 month and nothing... My periods are very light and what they call a scanty period. Will this affect us? Iv had my tubes tested etc at the hospital and they say I m fine, we don t fall into the category for a shot of IVF because there is nothing wrong with me, but we have tried 14 times now so something must be wrong??