I was supposed to start my period June 12. I am a virgin, for starters. Usually I m a day early, right on time, or a day late. At the end of May, when I suppose I was supposed to be ovulating, I was uber stressed due to a chemistry final. Then, I had to take the ACT June 14, and I was stressing the week leading up to it. Now, I leave for a mission trip Saturday, and I m really excited for it. Could the stress from tests or the excitement for my trip be causes for my late period? I ve been late before, just not in about a year. I ve only been on my period 2.5 years. Help?