Sudden shivers and chills when sleeping? Anyone know what this could be or have it happen to them?

Danielle • Living in LA with my husband and my pup. I'm a full time recruiter and a magical baby creator
I'm 21 weeks. The doctor office isn't open yet. I'm having random sudden on set of shivering and chills (although no fever, it's 77 in my home and very hot in California). Has anyone had this, I'm googling but can't find much. A sudden drop in something could cause chills, shivering cold right? I am not sleeping well but I don't know what it could be.