I think it is normal because my Wife to seen the Dark brownish discharge. We consult to a gynecologist it says it was an Old blood. So, i think you don't need to worry.
Lots of women do spot before their period starts up. Brown blood/discharge is old blood and not something to worry about. If you have it more often than a few days before period, talk to your doctor about it. It's nothing to worry about but might mean your hormones aren't in balance. good luck
I get brown discharge usually before my period starts and sometimes after. It's completely normal. :)