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.
It is often referred to in three parts called trimesters. The first trimester lasts 12 weeks, the second from 13 to the end of 27 weeks, and the third from 28 to 40 weeks. These divisions are somewhat arbitrary and you may encounter slightly different versions of these time periods during your pregnancy.lthough you will probably gain about 25 to 30 pounds (11 to14 kilograms) during the course of your pregnancy, only a small percentage of this amount will be gained during the first trimester. You may experience few signs of pregnancy and gain only 3 to 4 pounds.