Anal bleeding?! Freaking out!

So I’m freaking out just a little, I had bleeding in my anal area last night. It wasn’t bright blood, it was really dark. At first I thought it could be a hemerrhoid, but I have no pain or constipation at all, and as far as I can tell my butt looks perfectly normal. And it only bled one time and that was it, and also since the blood was not bright I’m pretty sure it wasn’t a hemerrhoid now. I feel perfectly normal today and have zero bleeding so it was just a one time occurrence. Is this something I should be concerned about? I’m wondering if I ate something bad. I have a doctors appointment next week, but that’s a whole lot of worry for a whole week.