When to call the dr?

While at work today I used the bathroom and noticed I was spotting a little bit, it was brownish pink, and it wasn't a lot, but it defiantly caught me off guard, than when I used the restroom again I had it again it was like a brown red, I'm trying to stay calm and relax since I've been on my feet the past 8 hours. Do I need to be alarmed and call the dr or go to the ER? Or am I ok... This is my first pregnancy and I'm ill be 7 weeks Sunday