Do you think my cat needs to go to the vet today or can wait until Monday?

Kitty has had a bloody nose off and on for about a week. It's only one nostril and started with a sneezing fit. I figured he popped a vessel in his nose and keeps reopening it with more sneezing. Last night, I noticed the nostril is now snotty and runny. Kitty is about 15yrs old. Does this need urgent care today? Just call for antibiotics? What do you think is causing it? I will be calling the vet when they open, but I wanted to see what y'all thought.