Could I not be pregnant anymore?

 In the beginning after finding out around 5 weeks, I was extremely fatigued all the time and I had light cramping occasionally accompanied with light back pains. My breats were tender and sore. Some days I just didn't want to eat and other days I ate normally. Zero morning sickness. 
Now it's 12th week and I'm realizing how "normal" I feel. I've been feeling this way for a couple weeks now. Hardly any fatigue, no more cramps or back pains, breasts are fine now except for nipples are still a little sensitive, I'm eating normally, basically I feel completely normal like how I was feeling pre-pregnancy. I feel pretty great in fact. 
I'm freaked out that it means something bad... Like a missed miscarriage?