Spotting during early pregnancy can be concerning, but it doesn't always indicate a problem. It's important to stay calm and follow your doctor's advice. Spotting can occur due to various reasons such as implantation bleeding or hormonal changes. The hormone injection you received may be aimed at supporting the pregnancy. Waiting until Friday allows your doctor to assess the situation further. If the spotting becomes heavy or is accompanied by severe pain or other symptoms, contact your doctor immediately. Remember that every pregnancy is different, and it's best to consult with your healthcare provider for personalized guidance and reassurance during this time.