Besides pregnancy, what are other causes for a missed period? i am having some pregnancy symptoms but don't want to limit it to just that.

Hormone issues: Your hormones, estrogen and progesterone, have to be in the right ratio to each other to have a normal menstrual cycle. Too little of one, too much of the other, and a cycle can get off. Those are the most common reasons. Otherwise, extremes of weight (thin/heavy), thyroid and pituitary are other common culprits. Hope that helps!