Symptoms in first month of pregnancy and are they all usually there?

First trimester: One of the earliest signs of pregnancy is a missed menstrual cycle. By convention, once you miss your cycle you are approximately 4 weeks pregnant. Other symptoms include breast tenderness, fatigue, low energy, sleepiness, and at times nausea. As pregnancy progresses, these symptoms become more apparent. You may experience some, all, or none of these symptoms.