Late period

So I was 4 days late on my period when it showed up out of nowhere yesterday. Usually I get cramps (pretty bad to where I need Tylenol) I didn’t have those, didn’t get my usual acne break out or crave chocolate. I was at the store when I got a sharp lower pain then felt the rush of blood. Woke up this morning to tampon underwear and pants soaked with more clots than usual. I had intense back pain last night (also not normal for me). Has anyone else had this? I did not have any positive home or blood tests but everything I see online points to a miscarriage.