Sometimes I find this white or yellow-ish milky substance in my underwear. Sometimes its moist, and sometimes it's dried up. And I have no idea what it is. I really don't know what it is or what it means. But I figured this was the right forum.
Could just be vaginal discharge. Completely normal unless it starts to smell, itch, become chunky, or green-ish. I wouldn't worry about it unless you're have those symptoms I just mentioned.
Yeah, that's normal. It's actually sort of what underwear is for, so that that stuff doesn't get on your other clothes.