Paula, this weekend, if you haven't already, go to an Urgent Care office and see a doctor. What you described could be one of a dozen things. It could be something as simple as what you ate or a prescription medicine, to something that needs medical treatment.
Um, what looks like coffee grounds is generally blood. Urgent care is a good place to start. Or if your insurance plan offers it, call the 24 hour nurse line.
It's blood and it is a very bad thing to ignore. Get to the ER unless you are on Hospice. Call the Hospice nurse if you are seeing this in a Hospice patient.