Can Vyvanse Affect Menstruation?

Can Vyvanse affect your menstral cycle? I'm 19 years old and have been on Vyvanse for about 6 weeks now, and I am a week late for my period. When I got off birth control in June of 2010 I did not receive my period for about 7 months. Then when I finally did it was pretty irregular but then slowly was becoming normal again. Now that I have been taking Vyvanse, I've lost about 10 lbs, sleep less, and I am more active. Could this be the reason why I am late for my period?