i feel for you...the waiting is awful! It's so hard being in limbo.

I hope that your HCG levels rise more and then you can see something in your uterus on the ultrasound. also if your hcg levels are rising at the rate they should, that's a good sign it's not ectopic...with ectopic they usually are lower than normal and rise slowly, or erratically (ie they can drop slightly, then go back up). sometimes i have heard 5 weeks is too early to see much.

I dont know thay my own experience will help you...but
i had an ectopic earlier this year. In my case they could see a sac in my uterus and thought I had had a missed miscarriage...I was sent in for a curette. after the curette though I stil had extreme pain, especially on one side (which I had had for some weeks), and my hcg levels were still high, and they then said they thought it was ectopic...my hcg levels went up and down and never went above about 900

I hope things turn out well for you