Bleeding

Hey guys I’m pretty sure I’m nearly 6 weeks pregnant, I went to the hospital 2 nights ago and they couldn’t find anything on the ultrasound as they said I’m pretty early but they done a blood test and said it’s all good as my levels are 675. I ended up going home and I’m still bleeding, I haven’t had any clots but it goes from bright red, to pink and brown. It doesn’t fill up a pad and there’s only heaps when I wipe. I do have mild cramps in my back and abdomen. I know you guys aren’t doctors at all but I want to see if anyone has experienced this and can give me a little bit of reassurance.