I don’t know....

Hi everyone 5w 3day baby number 2 never had any complications before

Last night I had a little dark brown blood when I wiped and same thing this morning so I went to the hospital to be checked out

My bloodwork urine everything came back I was pregnant

When they did the ultrasound they couldn’t see anything

So the drs told me they just didn’t know.... if it was a miscarriage or just too soon now I’m freaking out because they sent me home because they “just didn’t know”

Anyone else have this happen?

Someone please give me some advice. I’m freaking out I’m cramping with some mild bleeding