Or you may be unaware of any changes for weeks, only wondering if you're pregnant when you miss a period.
Though you may experience some, all, or none of these, here are the top 10 signs of pregnancy.
1. Prickling, tingling nipples
As pregnancy hormones increase the blood supply to your breasts, you may feel a tingling sensation around your nipples. This can be one of the earliest signs of pregnancy, and is sometimes noticeable within a week or so of conception.
Once your body gets used to the hormone surge, this sensation will subside.
2. Spotting and cramping
It's common to have some spotting at the time when you'd usually have your period. You may notice a slight pink or brown-coloured stain in your knickers, or when you pee, or feel slight cramping. Experts aren't sure why spotting in very early pregnancy happens, but it's thought to either be caused by the egg implanting in your uterus, or more likely, the hormones that control your periods kicking in.
3. Feeling sick
If you're lucky, you'll escape this completely. However, morning sickness is a common symptom of early pregnancy. It often starts when you're about six weeks pregnant, though it can start as early as four weeks. You may feel sick and queasy, or even vomit. Despite the name, morning sickness can affect you at any time of the day, or night.
4. Tender, swollen breasts
Once you are about six weeks pregnant, your breasts may become increasingly tender to the touch. It’s similar to how they feel before you have a period, but more so.
You may notice that your breasts are larger and swollen, with blue veins visible just below the skin. Tenderness tends to be most common in the first trimester, easing as pregnancy progresses.
5. Feeling tired
Exhausted? You may find yourself diving for your duvet as your body cranks up to support your baby, right from the early stages of pregnancy. Pregnancy hormones in your body are to blame, as these can make you feel tired, upset and emotional.
Though fatigue is not a sure-fire symptom on its own, it's a common pregnancy symptom. You may find that tiredness wipes you out the most in your first trimester and third trimester.
6. Needing to wee frequently
From about six weeks of pregnancy, you may notice that you're weeing more often.
This is down to a combination of pregnancy hormones, a larger volume of blood in your system, and your kidneys working extra hard. If you feel pain or a burning sensation when you wee, though, you may have a urinary tract infection (UTI).
7. Darker nipples
Skin changes are common during pregnancy. One of the first changes you may notice is the circle of skin round your nipples (areolas) getting darker. This can happen from about eight weeks.
You may also find that the bumps around your nipples become more pronounced, and your nipples more erect. Your vulva and vagina may change to a deeper, purplish red, too, though you probably won't notice this!
8. Food cravings and altered sense of smell
Food cravings can be a sign of pregnancy.
You may go off some foods, but develop a craving for others. This can happen very early for some women, even before they've missed a period. Some women report a metallic taste in their mouth, others that they can’t stand the taste of coffee or a food they usually like, such as eggs.
Your sense of smell may change as well, and you may find that you're more sensitive to aromas from food or cooking.
9. A missed period
If you're usually pretty regular, and your period doesn't start on time, you'll probably take a pregnancy test before you notice any other signs. A missed period is one of the surest signs of pregnancy.
But if your periods are usually irregular, or you lose track of when your next one is due, you may not realise that your period is late. In this case, tender breasts, feeling queasy and making extra trips to the loo may be early clues that you’re pregnant.
10. The proof: a positive home pregnancy test
Most home pregnancy tests will give you a reliable result if you wait until at least the first day of a missed period. If a blue line appears in the test window, you're probably expecting.
Talk to others who are hoping to get pregnant too.