Possible miscarriage ?

Amanda

So for the last week or so, I’ve had very light spotting.. nothing red.. but yesterday I was just sitting on the toilet and noticed some dark red spots in the toilet and if freaked me out! I haven’t had any spotting since, but I’m obviously concerned. My last ultrasound was a few days ago (still was spotting) but to my surprise, there was a yolk sac.. there wasn’t one last week! So I know, so far, things are promising.. but what could the bright bleeding be from? It kinda looked like a small clot, but idk. Doesn’t look like any tissue in it either.