you don't know that yet. There's a good chance it's normal so please please try not to get too stressed out.
I totally know how you feel having been through a m/c in Nov, and am now petrified throughout this pregnancy of repeat performance, but feeling stressed will make it worse. Try to remind yourself what a strong, good person who can deal with anything, good or bad. Pregnancy is sent to test us, i'm sure, but at this stage what you have is quite common and NOT neccessarily a m/c.
Have you got a friend or OH who could come and sit with you. Distraction or a hug will probably help
Fingers crossed and sending really positive thoughts to you
xxx