TW: blood/tissue but no mc?? HELP

to make a long story short a couple days ago i started spotting brown blood. (i’m 6 weeks). i didn’t think much of it until a couple days later it turned bright red and then dark red. i wasn’t bleeding a lot but it also was more than spotting. i went to the womens hospital they told me everything was fine, my hcg level were in the four thousands and the baby was okay. they said to go home and rest. that night i passed a big piece of tissue. it didn’t look like a sac or placenta and once it passed i stopped bleeding. so i went back to the hospital the next morning and they said everything still looks fine, the baby is still there but its heart is weak. my hcg level stayed the same. it also wasn’t a hemorrhage because they would’ve seen it on the ultrasound the day before. i’m not bleeding anymore but i also didn’t miscarry either. we’re just waiting to see what happens. this is so scary and stressful has anyone else experienced something like this?? what should i do? i dont want to lose my baby.