Symptoms may not start for 6 to 12 hours after exposure to the ultraviolet light. Symptoms include: 1  A feeling that something is in the eyes (foreign body sensation). 2  Sensitivity to light (photophobia). 3  Tearing.
It is divided into three stages, called trimesters: first trimester, second trimester, and third trimester. Conception to about the 12th week of pregnancy marks the first trimester. The second trimester is weeks 13 to 27, and the third trimester starts about 28 weeks and lasts until birth.
A normal, full-term pregnancy is 40 weeks, and can range from 37-42 weeks. Itâs divided into three trimesters. Each trimester lasts between 12 and 14 weeks, or about three months. Each trimester comes with its own specific hormonal and physiological changes.