Having cramping initially can be a symptom of the uterine muscle starting to stretch and the uterus trying to contract back. The cramping can also be the round ligament stretching but that is usually a sharper pulling pain that goes to your groin (the normal distribution of where your round ligament actually goes). If I understand your question correctly, a blood serum HCG of 9,000 was done; you are able to see a fetus with a beating heart at 5wk 2days so being told it’s too early at 9,000 is incorrect. The exception may be that you are pregnant with twins which would show 2 sacs by Ultrasound before it would show a fetus. However, you may have an empty sac or empty sacs or 1 sac with a fetus and 1 sac empty; in any of those cases, the placenta is what is registering the HCG test of 9,000. So if it is a singleton pregnancy with a single sac, your dates may actually be off; or you may also have a 2nd pregnancy sac in the tube or an ectopic; this can also give pelvic cramping with an empty uterus. And of course it’s possible to have a pregnancy in the uterus and in the tube at the same time; the ectopic pregnancy in the tube is a medical emergency that will grow and rupture the tube causing internal bleeding, possible hemorrhage and can be fatal so make certain you quiz your healthcare provider about all of these possibilities before settling on the explanation you are given.