You should be able to take off as long as your pregnancy is healthy and you have been cleared by your doctor. There are some additional steps that you can take to feel safer and more comfortable while flying (via WebMD). Be sure to bring anti-nausea medication and gas and diarrhea remedies along with prenatal vitamins. Also, make sure to get your flu shot before leaving.
During your flight, it’s best helpful to avoid eating any gassy foods, like beans, or drinking any carbonated beverages if they serve food and drinks on the plane. However, it is important to drink plenty of fluids and water throughout your flight. You should also ensure that your seatbelt is securely fastened as long as there is a fastener. Keep it below your belly. If the sign is not on, it’s a good idea for you to move about and get up if there’s no turbulence.