NORMAL PREGNANCY First trimester - is from the date of last period to 12 weeks of gestation. During this period the body undergoes certain changes to accommodate the pregnancy. During this period women are most symptomatic. Second trimester is from 12 weeks to 28 weeks of gestation. The major events during this period is that the expectant mother starts feeling the fetal movement which is called as Quickening between 20 - 24 weeks .