Stretching vs miscarriage

Alexa
So I have a 1 and a half year old son and I had a miscarriage in July I'm currently 4 weeks pregnant and I'm having cramps. Idk if I'd describe them as cramps I guess. When I had my miscarriage nothing seemed out of the ordinary until I started to bleed. My stretching vs the cramping I had during my miscarriage weren't different from one another. Also when I found out I was pregnant with my son I was over a week late and thought I was just stressed and it felt like my period was going to come. But I had no worries then, now after the miscarriage I'm freaking out about every tweak and twinge!  
I have an appointment December 6 for an ultrasound and I'm just counting down the days. 
Sorry for the rant. I just had to get this off my chest and not be the only one knowing I'm worrying about this!
Thanks for reading!