1 Use moderate intensity, which is sufficient to improve cardiovascular fitness, muscle strenght and flexibility. 2  Perform exercises regularly: cardiovascular exercise: 3 to 5 times per week, strenght training: 2 to 3 times per week.
The pregnancy starts from the first day of her last menstrual period. Normally 2 weeks before ovulation. An ultrasound is the most accurate way to determine pregnancy dates. So yes, she can be 6 weeks and 3 days pregnant even though you only met 5 weeks ago because two of those weeks were before conception.
In the second and third trimesters, the most accurate way to determine gestational age is by measuring the baby's head circumference, abdominal circumference, biparietal diameter, and femur (thighbone) length. Nuchal translucency screening also involves using an obstetric/prenatal ultrasound.