I had milky white sticky discharge on my underwear and i don't have a uti what could this be from ??

Vaginal Discharge: Depending on if you are sexually active, it could be from a sexually transmitted infection. If you have taken antibiotics recently, or from other factors, it may also be a yeast infection. It could also be physiologic discharge, which is normal, depending on what part of your menstrual cycle you are in. I suggest making an appointment with your physician to discuss further. Take care.