Early Pregnancy: Understanding Lower Abdominal Sensations & Ultrasound Findings

Question
This may seem silly, but I'm worried that I don't feel anything in my lower abdomen at this time (and I'm pregnant). My last menstral period was July 24th, and I ovulated on August 11th for certain. I've already had one ultrasound, in which they found the gestational sac (only, not yolk sac or fetal pole) at 5 weeks and 3 days (from last menstral period). Is this normal to only see that, and nothing more at that stage? Also, I'm concerned because besides tender breasts, I don't feel any symptoms yet - and I'm especially concerned that where I am now (around 6 weeks today), that I don't feel any pulls or twinges or cramps or anything in my abdomen. Shouldn't I be feeling SOMETHING by this point?

Answer
The earliest symptoms of pregnancy are breast tenderness, fatigue, and nausea. There are no other early symptoms of pregnancy. After a few months, you will start feeling movement of gas in your intestines and occasional cramps. However, at 5-6 weeks you will not feel anything. A sonogram will not show a fetus or a fetal heartbeat until 6-7 weeks gestation. At this stage, you will only see an empty gestational sac on sonogram. You will not feel any fetal movement until 22 weeks gestation. Don't worry.