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.
1st trimester ultrasound is the most accurate. But a 2 nd trimester ultrasound is also quite accurate and in fact is usually more accurate than the last menstrual period! That's because your due date from your period assumes you ovulated 14 days after the first day of your last period.