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.
First Trimester. The first trimester consists of weeks 1-12 of pregnancy. The first trimester is a very important time during pregnancy, when all of the pieces are falling into place to grow a healthy baby. You may not look pregnant during your first trimester, but you can be sure that many changes are taking place.