It's normal to have some vaginal discharge, as the vagina stays moist as part of its self-cleansing mechanism. The normal moist discharge clears dead cells and bacteria from the vagina. It comes mainly from glands in the cervix (the neck of the womb), and is slightly acidic, which helps to keep infections at bay. The acidity results from lactic acid, formed by 'friendly' bacteria as they break down sugars.
The amount of normal discharge varies from woman to woman, and with the menstrual cycle. Many women notice that during the week after a period there is hardly any discharge, and what there is has a thick consistency. Towards the middle of the cycle (about 2 weeks after the start of a period) the amount increases and it becomes thin, slippery and clear, like uncooked egg white. When this discharge is exposed to the air it becomes brownish-yellow, so it is normal to find a yellowish stain on your undies at the middle of the monthly cycle. There may also be a feeling of moistness and stickiness.
Discharge also increases during pregnancy. And during sexual excitement, vaginal discharge becomes very profuse because two glands near the vaginal opening (the Bartholin's glands) secrete additional slippery mucus, which acts as a lubricant for intercourse.
Hope this helps in some way, I don't think from your description you have anything to be concerned about.
