5wks Pregnant and my fatigue went away. Did your fatigue go away early or is this beginning sign of m/c?

First beta was 462 (should be around 100). This was a good start. Strongest symptom was fatigue. Did not have sore but had 2.spells of slight naseau. Three days ago my symptoms left... just lke that. I am full of energy as I was also yesterday. I know that I could be early to experience some pregnancy symtpoms, but to not be tired anymore really scares me. My 2nd beta is tomorrow to make sure my HCG levels are increasing. I have had a m/c before and my lack of and dissapearing symptoms scare me. Has your fatigue just left in your early pregnancy stage or did you have a m/c?