Waiting 3 weeks..?

Marie
AF has been 2 weeks late before and not pregnant, so I am considering wait til AF is 3 weeks late before I take a pregnancy test. Is that crazy? I hate wasting money on tests and getting my hopes up but I also don't think I can wait that long (AF due this weekend, so no test until 4/18 if she doesn't show!) Has anyone else had a similar experience?