Pregnancy signs come and go. Mine "stopped" sround 9 weeks then are back now at around 27 weeks. One day you will have morning sickness then the next day nothing. Good luck!
I posted the same worry the other day, and a few women wrote in to reassure me that "feeling" pregnant one day and not the next is common. Three days later, the nausea and fatigure were back. Enjoy the temporary relief from your symptoms....
I dont want to alarm you in any way, but I experienced the same thing last month, right before I ended up miscarrying. My symptoms all of a sudden completely disappeared. No more heartburn, no more tiredness, and boobs completely no longer tender anymore. There are a lot of cases where this is normal in a healthy full term pregnancy, and thers cases where this could be a sign of a problem. When I was diagnosed with a m/c they said the baby stopped growing 2 weeks behind, which was exactly when my symptoms had stopped. Again, everyone is different, and im not here to scare you, just to inform you. Pay a visit to the Dr. to get your hcg levels checked out. Better safe than sorry.
Good Luck, and Best Wishes!