is brown discharge normal during early pregnancy?

I would call your doctor to let him or her know. You're 8 weeks and that's too late for it to just be implantation bleeding. It could be nothing, but it could be a sign of something serious.

When I was about 6 weeks along with my second pregnancy I started having some brown discharge. At 7 weeks I had some bleeding and was diagnosed with a threatened miscarriage. Everything turned out just fine, it was just some random spotting. But, that isn't always the case, so it's best to let your doctor know.