Also, some women feel no symptoms at all, or only some. Your energy drop is a definite symptom and like the other poster said, you are fairly early in your pregnancy. You may start to feel other symptoms. Sore breasts, cramping from stretching, constipation, food aversion, cravings, back aches, sinus congestion, frequent urination, etc. I didn't get full swing into most of mine until the 6th week. I'm sure your fine. Be thankful!