Pregnancy calculator: A week-by-week pregnancy calendar

As you track pregnancy, you probably know how many weeks you are, but what about how many months? You might also be curious to know how far along in your pregnancy you are so you know how long it’s likely to be before you get to meet your baby for the first time.

This is where our pregnancy calculator comes in handy. Keep reading to learn more about how to use it, along with some expert pregnancy advice from Dr. Renita White, obstetrician and gynecologist, Georgia, US.

• Please note that Flo Health does not collect, process, or store any of the data that you enter while using these tools. All calculations are done exclusively in your browser. Flo Health does not have access to the results. All data will be permanently erased after leaving or closing the page.
• Our Pregnancy Calculator is based on a 40-week pregnancy. As we cannot know when exactly your baby will be born, the calculator is not 100% accurate.
• Remember that pregnancy calculators, pregnancy due date calculators, and birth date calculators can help you learn more about your estimated due date and pregnancy time line, but they are not a replacement for medical advice. You should always notify your health care provider that you are pregnant. An ultrasound will be needed to date your pregnancy.

How to use our pregnancy calculator

Our pregnancy calculator uses some basic information to figure out how far along you are. All you need to do is input how many weeks and days pregnant you are, and the tool will do the rest.

Once you enter the data, you will get a personalized overview of your pregnancy in months so far. This will include a percentage of how far along you are, how many months pregnant you are, and which trimester you’re in. You’ll also be able to click through to an in-depth article that will tell you about what’s happening during that specific week of your pregnancy. Plus, if you’d like an idea of when your due date is likely to fall, you can use our due date calculator, too. Additionally, you can check out our implantation calculator to find out when the implantation might have occured. Clever, huh?

Week-by-week calendar

Pregnancy is an exciting time filled with lots of change — for both your growing baby and your growing body, so you’ll no doubt have lots of questions. Those questions might include: What developmental milestones happen as the weeks go on? What symptoms can you expect and when? And what things should you be thinking about each step of the way? We’ve spoken to Flo experts to bring you the essential knowledge you need for your pregnancy, week by week. Simply scroll through our carousel below to find your week of pregnancy and learn more.

What is a trimester?

First up, let’s go over the basics. What exactly is a trimester? “A trimester represents the three sections of time periods of pregnancy,” explains Dr. White. “These periods represent the 1st, 2nd, and 3rd trimesters [up until you give birth].”

How many weeks are in each trimester?

Counting from your last menstrual period, there are 13 complete weeks in the 1st trimester and 14 complete weeks in the 2nd trimester. The amount of weeks in your 3rd trimester will vary depending on when your baby is born, so if you’re wondering how long a pregnancy lasts, there’s no specific answer. Your due date marks 40 weeks of pregnancy (or 9.2 months!), but it’s common for your baby to be born on a different date. In fact, only around 5% of babies are actually born on their due date.

You might also be wondering why your health care provider is counting your pregnancy in weeks rather than in months or even just trimesters. Over to Dr. White. “Many things can change rapidly in a pregnancy, even week by week,” she explains. “Also, some tests and evaluations are needed at specific weeks of pregnancy. So for more precise management and observation, it is better to evaluate pregnancy by week.”

Tips on having a healthy pregnancy

Having a healthy pregnancy not only helps to support your baby as it develops, but it also helps to support your body as it adjusts to all the changes that pregnancy can bring. But what are some essential do’s and don’ts to consider when planning a healthy pregnancy?

Do have a healthy pregnancy diet

When it comes to a healthy pregnancy diet, there are a few things to consider. First of all, the usual healthy eating principles are the same in pregnancy as they are at other times — it’s good to eat a balanced diet with lots of fruits, veggies, lean protein, healthy fats, and whole grains. However, there are some foods you need to avoid, including foods made from unpasteurized milk and raw or undercooked meats, because of the risk of bacteria and sickness. You can find out more in our guide to a healthy pregnancy diet.

Do get the right nutrients

Alongside a healthy diet, you might also be considering taking a pregnancy supplement to help you get all of the nutrients that both you and your growing baby need. One of the most important nutrients is folic acid. Experts recommend you get 600 micrograms per day during pregnancy; you should be able to get some of this from your diet, and you’ll need to take a daily supplement containing at least 400 micrograms of folic acid. But why? “Folic acid is very important in brain and spine development of the baby,” explains Dr. White. “Most importantly, it is vital for the development of the neural tube. The neural tube is part of the early central nervous system.”

Other recommended nutrients include:

• Iron
• Calcium
• Choline
• Vitamin D
• Omega-3 fatty acids
• B vitamins
• Vitamin C

Always speak to your health care provider before taking any new supplements.

Do keep exercising

Pregnant women are advised to do around 150 minutes of moderate-intensity exercise each week. And, if you feel able to, keeping up with a healthy workout routine can have many benefits. “Exercises can help with alleviating common pregnancy-related pains, including back and joint pain,” explains Dr. White. “It can help you maintain a healthy pregnancy weight. It has also been shown to decrease the risk of gestational diabetes and shorten your length of labor.”

If you were active before your pregnancy, it’s probably a good idea to decrease the intensity of your workouts. If you weren’t active, experts advise that you start slow when it comes to introducing exercise into your pregnancy routine. It’s also a good idea to avoid any contact sports or workouts that involve any risk of falling to help keep your baby safe and protected. It’s always a good idea to ask your doctor any questions you have about exercising safely during pregnancy.

Don’t smoke, take drugs, or drink alcohol

“Smoking cigarettes and illicit drug use should absolutely be avoided in pregnancy,” says Dr. White. “It can have a negative impact on a baby’s development as well as the development of the placenta. This can lead to fetal growth restrictions, preterm labor, and placental abruption (where the placenta detaches early before the baby is ready to be born).” 

She adds that: “Alcohol use also has the potential to impact a baby’s development. Since we don’t know how much alcohol it takes to negatively impact a baby, we recommend avoiding it altogether.”

Of course, these tips aren’t the only things to consider when planning a healthy pregnancy, but they’re a good place to start. Remember to always chat with your health care provider for tailored advice that’s specific to your own pregnancy. You’ve got this!