Magick doesn't really rely much on your blood. It relies on your confidence/belief/faith. You must be confident in yourself, believe that what you do will work, and have faith in your ability once you have done your part. When you cast your spell consider it already done. Don't worry about what your goal is/was, consider your goal accomplished and that time just has to catch up with reality. Know that you were successful, don't just think you might have been.