Brown discharge stains in panties?

I’m 18 years old and have only been sexually active once a year ago. I’m also not on my period and haven’t been during the time span I’ve had this pair of underwear. After a couple of times of wearing a new pair of underwear there will be a brown stain there after a few washes. Is this normal? Has anyone else experience this? My discharge is always clear and sticky but I think it dries brown or something. I don’t have a yeast infection because I have had them and know what they feel like.