Dark spotting while pregnant.

I really didn't want to post this but I'm just really confused... I'm supposed to be 6 weeks pregnant. But about 8 days ago I started spotting very very light brown and it was only the tiniest amount after peeing. And then it did eventually go away for one day. But it's started again the next and over the last few days it's just been getting heavier and darker. I had a scan yesterday and they couldn't make out much because I'm so early on. My hcg levels are all fine... but somethings just jot sitting right with me... is this OK? Sorry about the TMI photo I'm really embarrassed :(