Some early symptoms of pregnancy include nausea with or without vomiting, fatigue, food aversions or cravings, swollen and tender breasts, and increased urination. These symptoms, in addition to a missed period, can begin to occur as early as a few weeks after conception, according to Mayo Clinic.
After the early signs of pregnancy, other symptoms can surface in the later stages, around the third trimester. Later symptoms of pregnancy include continued breast growth and swelling, backaches, shortness of breath, heartburn, and weight gain. Individuals can also experience Braxton Hicks contractions, weaker contractions than true labor ones that come and go unpredictably, as stated by Mayo Clinic.
Pregnancy occurs when a sperm cell comes in contact with, fertilizes an egg, and the fertilized egg implants itself in a woman's uterus. Once fertilization occurs, it can take up to seven days for implantation to occur. The egg begins to divide into a ball of cells, and those cells travel down the fallopian tube to the uterus for three to four days. It floats in the uterus for two to three more days before attaching to the uterine wall. Typically pregnancy lasts for nine to 10 months, or 40 weeks, according to Planned Parenthood.