During the third week of pregnancy, many women may not even be aware that they are pregnant yet. However, there are a few early signs and symptoms that can indicate pregnancy at this stage. These include implantation bleeding or spotting, mild cramping, breast tenderness or sensitivity, increased vaginal discharge, and changes in cervical mucus. Some women may also experience fatigue, mood swings, and heightened sense of smell. It's important to note that these symptoms can vary from woman to woman and not all women will experience them. If you suspect you might be pregnant, it is recommended to take a home pregnancy test or consult with your healthcare provider for confirmation.