discharge

Has anyone else had brown discharge? I'm 7 weeks today. It started last night and was super super light (almost not noticeable), and is a little heavier today. I don't have cramps, I'm still neauseous like I usually am. I know everyone says it's normal, and brown means old, but I'm still REALLY nervous.. it's mostly when I wipe, and only a teeny tiny bit on my underwear.. anyone else have this and things are perfectly fine?! Is there a point I should call my doctor?