I think that unless you have a bleeding tooth/gum, anything that has blood should be a call for concern. Better to see your doctor soon.
I agree with Pink5622. If it isn't an oral hygiene problem, then this should be followed up on with your doctor. This could be upper GI bleeding due to your Gerd which is currently untreated. I do understand about Zantac and would say you also need to talk to your doctor about an alternative medication. I would call your doctor today to be seen!
I’m alternating Pepcid for two weeks with Zantac for two weeks for GI inflammation. The FDA has dialed back a bit on the Zantac issue. Not sure I trust that, but it was never an extremely concerning report. If Pepcid continues to work I’ll ask my doctor if I can take it regularly.