nipple discharge

hi i'am 27years old and i mist my period and i think i could be pregnant. 5 days ago i was in the shower and i saw that my nipples were very swollen and my veins on my breast are very noticable. so when i came out i don't know why but i squeezed my nipples and a clear yellowish liquid came out.. can someone please tell me if that is normal or why that might be happening and my last period was on 10-28-07..  

[Cleveland Clinic]

Dear molly1080:  Many women have some type of nipple discharge or fluid when their breasts are squeezed, and its normal. Squeezing the nipple sends message to the brain and the pituitary gland responds by increasing prolactin levels, which in turn produces discharge from the nipple.  The discharge can come in a variety of colors - gray, green and brown as well as white.  Some women are more prone to more discharge including women on; birth control pills, certain blood pressure medications or on major tranquilizers.  These medications increase prolactin levels in the body.   There is also certain life periods when a person is more likely to get discharge than others: there may be more discharge at puberty and at menopause than the years in-between.  Prolactin levels may also be increased in pregnancy. The time to worry about nipple discharge is when it’s spontaneous (comes out by itself without squeezing), keeps on happening, and is only on one side.  If it is clear and sticky, like an egg white, or bloody.