I'm scared and I don't know how to stop it

I'm honestly petrified. I just found out yesterday that I'm pregnant and Glow is placing me at four weeks and three days and my period would have started tomorrow. The cramps are kinda painful but not overly so plus I'm a wimp anyway so painful to me could be way different than most other peoples painful, they feel like period cramps and are freaking me out. It's at least once every hour. I'm scared of the chance of a miscarriage. This is my first pregnancy so I don't know what my body will do and that scares me even more. I just need advice and tips and facts and some reassurance right now.