I would not wait, if the discharge is still there the first or middle of this week and she is not in season by then, I would get her checked out, just for safety.
Often you will notice a slight discharge when a female is going into, or is "in season". When she is "in-season", she will be slightly swollen in that area and you should be able to see a tiny touch of what looks like a drop/spot of bright red blood just inside, but still visible. If not, and she does not show this soon (as in my the first to the middle of the week) .... I would take her to the vet and get her checked out, it could be the first visual sign of an infection ... may not be, but why put her at risk? I would not ... chins die when you don't get them checked by a knowledgeable vet when you should.
Chinchillas are very good at hiding their illness, often until it is to late. This comes from a natural instinct that kept them from becoming prey in the wild. If a chin showed any sign of weakness, illness or injury in the wild, it became easy prey. This natural instinct is still with chinchillas today, even in captivity and is often their doom.
Is this female in breeding? If so for how long? Many breeders/ranchers swab the females on a routine basis before they put them into breeding.
How old is she?
Is she caged alone or with another chin? If so, is the other chin a male or female?
Has she ever had any kits?
Jo Ann