I only have my period once a yeardoes that mean i'm not able to get pregnant except one week a year?

Rare menstruation ?: A "period once a year" is unusual unless the cause is polycystic ovarian disease, as it usually reflects no ovulation as the cause. Your chances of pregnancy will be enhanced if regular ovulation can be established. See a reproductive endocrinologist to determine the cause, if pregnancy is desired, but a gyn physician if not, and oral bcp's may be helpful to avoid long term estrogen effects.