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 pregnancy lasts for about 40 weeks. The weeks are grouped into three trimesters. The first trimester is the time in between fertilization of the egg by the sperm (conception) and week 12 of a pregnancy. A woman's body goes through many changes during the first 12 weeks of a pregnancy. Women often start to have concerns over: what to eat.