Your first trimester is coming to an end, and you may be excited, exhausted or both. The idea of becoming a mom is probably starting to sink in. Although you may feel you still have a long way to go to meet your baby, it’s great to know you are a third of the way through pregnancy.

What’s happening with your body?

By week 12 of pregnancy, your uterus is getting too big to be contained in the pelvis. It rises into your abdominal area, which means you may have a little bump. If you still don’t look pregnant just yet, you will probably start to show in a few more weeks. Keep in mind, if this is your first baby, you may not show until a little later in your pregnancy.

Between a thickening waist and bigger breasts, you may be ready for maternity clothes. Even if you are still wearing your regular clothes, loose fitting outfits may feel most comfortable.

Some of your early pregnancy symptoms, such as fatigue and breast tenderness, may be easing up at 12 weeks. But you may develop a few new symptoms, such as lightheadedness. During pregnancy, progesterone levels increase. Progesterone causes your blood vessels to widen, which increases blood flow to your baby. But blood flow back to you slows down a bit, which can lower blood pressure and can result in lightheadedness.

Headaches may also develop at this stage in pregnancy. If you suffered from migraines before becoming pregnant, they could become worse during pregnancy due to hormonal changes. Pregnancy insomnia and fatigue can also contribute to headaches. Be sure to talk with your doctor become taking any medication.

Keep in mind, pregnancy does not just bring physical changes, you may feel some emotional ones as well. Some women love being pregnant and are excited and upbeat most of their pregnancy. But symptoms, such as nausea and fatigue, can get you down. It’s also normal to have days you feel stressed about your impending responsibility. If you are not feeling overjoyed every minute, don’t feel guilty. Pregnancy can be tough emotionally and physically for some women. It may help to talk to someone about your feelings and don’t hesitate to get help if you feel overwhelmed or depressed.

What’s happening with your baby?

Your baby is changing quite a bit. He has almost doubled in size in the last few weeks and is about as big as a lemon. By the end of week 12, most of his systems and structures are formed. For the next 28 weeks, your little one’s organs will continue to mature. His organs are already becoming more sophisticated. For example, his digestive tract is starting to contract, which is how food moves through his system. His head is also becoming more proportionate to the rest of his body, and his nerve cells are multiplying quickly.

Your baby is also developing complex reflexes. His little fingers can now open and close, and he can make sucking noises. For right now, your baby is getting all his nutrients through you via the placenta. But the sucking motion is good practice.

Things to keep in mind

If you suffered from morning sickness your first trimester, you may soon start to feel better, which may mean you can eat more. Keep in mind, eating for two does not mean you get to eat twice the amount of food you normally did before pregnancy.

During your first trimester, you don’t need any additional calories. When you hit your second trimester, you need about 350 more calories a day and by your third trimester, you need about 500 more. So although you do need to take in more calories, it may not be as much as you thought.

An extra 300 to 500 calories could be the equivalent of a few healthy snacks, not a whole pizza. Good choices include a yogurt and fruit smooth and a bowl of cereal and milk.

If you are carrying more than one baby or started pregnancy underweight, your doctor will likely recommend you gain more weight. But for the average woman, a weight gain of 25 to 35 pounds is usually recommended. Don’t stress if you don’t stick to this exact number, and talk to your doctor if you have any concerns.