It is not uncommon for pregnant women to experience symptoms such as a sore throat, phlegm, and light-headedness. These symptoms can be caused by various factors including hormonal changes, increased blood volume, and the body's immune response. However, it is always important to consult with your healthcare provider to rule out any underlying conditions or infections that may require treatment. In the meantime, you can try some home remedies like staying hydrated, gargling warm saltwater, using saline nasal sprays or drops to alleviate congestion, and getting plenty of rest. If your symptoms worsen or persist for an extended period of time, it is best to seek medical advice for proper evaluation and guidance specific to your situation.