Spotting

Amber
Ok so I've never had spotting before, but I started spotting about a week ago and it's brown which I know means it's old blood, but is it safe for it to be going on for so long? I know it's not my period because it's so predictable plus I'm on birth control and my next period is in about 2 weeks. I'm just worried because it hasn't stopped in a week and it's all brown