I am on Seasonale birth control and therefore only get my period once every 3 months. I am sexually active, but take my pill on time all the time and use the "pull-out" meathod (I know, not very smart). Normally I have very short periods, about 3 days, but this time it has been about a day of regular period and now on the second day it's ending. I had my normal PMS symtoms (breaking out slightly, irritability, & wanting snack foods). I don't know if it has been short due to change in my body (in the past 3 months i have become VERY physically active and gained about 7 pounds of muscle) and because of stress (college student with finals coming up). Do you think I should worry about being pregnant?