Mother (89), just called to tell me she is bleeding ,like a period. Is this a emergency situation?

I agree with what FF says. Especially as this is a holiday weekend, I'd get her in to see someone now. And yes, if on blood thinners, 911.

I suggest take Mom to an Urgent Care clinic or Patient's First [whatever is in your area] if the bleeding is a spotting. If it is something that cannot be stopped [due to blood thinner meds], call 911 immediately.