Missing a period fundamentally means that during ovulation an egg produced by the ovary flows into the fallopian tube. When the sperm reaches the egg, you get pregnant. And, the fertilised egg moves into the uterus. This is about the size of the head of a pin. Do not be disappointed by the description. That’s what the doctor will tell you, too. It is not called foetus yet because it is right now just a bundle of cells which are multiplying at a phenomenal pace.
Much later you will realize that the outer layer of these cells become the placenta and the inner layer of cells the embryo. That head of the pin is the result of the egg getting fertilised. It gets implanted to the lining of the uterus. The external implications of all this is that you could probably experience fatigue, nausea which may be accompanied with or without vomiting, craving or aversion for food and some weight gain.
Put don’t get over excited with all the craving. You don’t have to start eating for two persons. Not just yet, at least. Yes, your breasts will feel tender and, may be, even sore. The doctor will prepare the time table for you for the next nine months and decide if you require any supplements to meet the growing demands of pregnancy.
A small word of caution here. While a home pregnancy kit, the first step for most women when they skip their menstrual cycles, be aware that the results can also produce false positives. Do not rely on this test alone and consult your gynaecologist at the earliest.