If you are already employed, you likely wonder if you should reveal your pregnancy to your employer. Again, you do not have to do so, but you might want to in case you are discriminated against. You cannot prove pregnancy discrimination unless you can prove that your employer knew that you were pregnant. While you might not want to announce your pregnancy during the first trimester, it is wise to make a record of it once you begin to show. If your employer takes adverse action against you after being notified, you can prove discrimination.