My sister-in-law just had the same thing, brown color spotting. They had a scan and everything was great. It seems to be old implantation blood getting pushed out. If you're 8 weeks you might as well get an early scan just to double-check but I'm sure it's fine. And tell your dr. It's when you bleed bright red blood that you need to worry.
just keep an eye on it it could be something and nothing if it gets any worse wee your gp :) x
p.s we're not docs its just a medical advice forum altho you can join a professional forum too on here x
Many woman experience spotting/bleeding in first trimester,brown spotting means old blood but you must report it to your doc,he will ask you to go for scan then he will be able to tell you what is causing it Want to mention this is not a Doc forum and none of us here is a Doc.