The discharge is likely from the sweep itself and I don’t think it would be a sign of anything else. I had zero dilation (so they couldn’t even perform a sweep) and my water broke / I went into labour naturally a week later. Don’t be discouraged if you’re not dilated. Our bodies know what to do and you can go from 0-10 in hours.
The sweep probably made you bleed. Not necessarily a sign. I was 1cm, engaged etc had two sweeps, lost bits of my plug, bled, got cramps etc neither worked. They're not a guarantee. If your cervix is closed/not dilated I'd say you're probably not ready enough so it won't work.
A sweep can cause some bleeding, I had this after mine and it looked like brown discharge too. Not really a good or bad sign just completely normal. Everyone's different but i was 2cm dialated and 40+1 when I had my sweep on a Tuesday, baby came on Sunday