Hcg chart lady here! go to http://www.americanpregnancy.org/duringpregnancy/hcglevels.html
It's helpful (i think) and may put your mind at ease! Good luck.....
You're probably fine. At 5-6 wks the heartbeat WILL be low. What were your HCG levels? Someone here has this amazing little chart that shows you what your HCG levels should be around that time. The thing about HCG is that one woman could be at 700 and another at 1200 (both the same age pregnant) and it is normal. There is a wide array of normal HCG levels.
What needs to happen is your baby's heartbeat needs to reach over 100 soon (I'm not sure when). Have you gotten your progesterone and HCG levels checked to make sure you don't have low progesterone.
Women get their dates mixed up all the time! I've heard of so many women who were at least two weeks off with how far along they thought they were. I would just relax, put you feet up and go back to the doctors in a week or two. And just monitor how you are feeling. Cramping isn't always a bad sign...your body is changing and preparing to give birth to your baby. I would only worry if you start to bleed or pass any clots.
What did the doctor say to you?
I wouldn't worry hun, it's amazing what a week can do...I know it'll be hard to wait it out but I think thats your best bet, unless something chances in the meantime. Good Luck!
I am only measuring 5-6 weeks and I thought I should be at 7-8 weeks.
Did they tell you that you were possibly miscarrying? You may have had your conception date wrong. It happens, even to the most responsible of us. If that is the case, then it'd be normal to measure earlier. Cramping is a normal pregnancy symptom as the uterus and ligaments are stretching.
As far as your HCG levels, it depends on how far along you are. How far along are measuring?