Any advice ?

I’m about 6 weeks and 3 days pregnant and just two nights ago I went into the bathroom and when I wiped I had some dark red blood on my toilet paper and it was just that one time. I haven’t bled since and it wasn’t heavy and it started to turn into a light pink red and then it turned into a brownish color. I haven’t had any cramps, but decided to go to the E.R since I’ve had two previous miscarriages. They ran my blood and did an ultrasound found the sac, but not the baby :( doctor said I might be too early on to see baby, but I’ve seen ladies go in at 5 weeks and they see a vital heartbeat and baby. I’m really scared I go back Tuesday to see how my levels are doing. Do you guys have any advice ? Anything would help thank you 💜