How soon can you have signs of pregnancy that people notice?

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. At 12 weeks gestation the uterus grows above the pelvic bone and your stomach starts to bulge.