It is always nerve wracking, but entirely normal when symptoms stop. If you have not had an ultrasound done, I would suggest calling your doctor and getting scheduled. Since you don't mention having any bleeding, I think there is a pretty good chance that everything is OK.
This does sound very scary for you but the symptoms going is just one of the symptoms of a posible miscarriage! Try to be hopeful and not to worry to much. Lots of love xx