Third, the gravitational effect of the moon is just as potent during new moonsâwhen the moon is invisible to usâas it is during full moons. There is a more serious problem for fervent believers in the lunar lunacy effect: no evidence that it exists.
Answer: Each pregnancy is divided into three trimesters. Each trimester is roughly a third of your pregnancy. These three trimesters have different emotional and physical happenings that make them unique. Here is a guided tour through each trimester:
Pregnancy is measured in trimesters from the first day of your last menstrual period, totaling 40 weeks. The first trimester of pregnancy is week 1 through week 12, or about 3 months.The second trimester is week 13 to week 27. And the third trimester of pregnancy spans from week 28 to the birth.Your baby will change from week to week.To learn more about how your baby is changing each month and about what tests you might think about having, see the Interactive Tool: From Embryo to Baby in 9 Months.regnancy is measured in trimesters from the first day of your last menstrual period, totaling 40 weeks. The first trimester of pregnancy is week 1 through week 12, or about 3 months.