The Acute Effect of Physical Exercise in Pregnancy

The goal of this crossover clinical trial is to investigate the acute physiological effect of exercise on the uterine and fetal blood flow in pregnancy. The main questions it aims to answer are: * What is the acute physiological effect of exercise on the uterine and fetal blood flow in pregnancy? * What is the acute physiological effect of continuous aerobic exercise versus resistance exercise on the uterine and fetal blood flow in pregnancy? * What is the effect of physical activity levels on the uterine and fetal blood flow in pregnancy? Researchers will compare the continuous aerobic exercise to the resistance exercise with a 3-6-week interval to examine the acute physiological effect on the uterine and fetal blood flow. Participants will: * Fill in a physical activity level questionnaire at baseline. * Complete either continuous aerobic exercise or resistance exercise and take blood flow measurements. * Complete the remaining type of exercise after a 3-6-week interval and take blood flow measurements.