Are sore abs the start of my miscarriage?

I’m supposed to be miscarrying soon per ultrasound I had. I’ve miscarried before but I never knew about it in advance before bleeding started. And both experiences were pretty dif.

Last night laying in bed, I felt nauseous, kind of shaky, and cramping in uterus. I’d feel something going on in my abdomen sometimes. I thought the miscarriage was starting. But I guess not, I went to sleep and feel pretty normal this morning. But my abs feel sore and almost achy today.

Is this a sign of a miscarriage? Could it be contractions? It almost feel like I did a ton of crunches and my abs are sore

I never felt my contractions when I was in labor with my daughter til they got bad, so I’m not really sure what they feel like anymore.