Not necessarily. Students taking the ACT have the option to choose which test date's scores to report to colleges. Students taking the SAT have a similar option to choose which tests to send to colleges, although some colleges are requesting applicants to report all scores. Just remember not to get too caught up in taking and retaking these tests numerous times, as your transcript is the most important part of college admissions evaluations.
Students are allowed to choose which test date of the SAT they want to submit (both the Evidence-Based Reading and Writing and the Math score will be reported). For Subject Tests, students are allowed to select which individual test results to submit to colleges, even if multiple tests were taken on the same day.
It is always the student's responsibility to make sure that test scores are reported to colleges. Students do so for the SAT through the College Board (www.collegeboard.com) and for the ACT through the American College Testing Program (www.actstudent.org) websites. Consult with your adviser before reporting any scores to colleges.