What is going on!!😣😢

My last 3 hcg levels were 1153, 1824, 3735, all were 3 or 4 days apart... I've had brown spotting on and off for about 5 days now and my ultrasound today showed a empty gestational sac.. I was told to come back in 2 weeks for another sonogram.

I'm not sure what to do and I don't want to get my hopes high anymore.. I'm supposed to be around 6 weeks now but with the ultrasound finding and the spotting, I'm freaking out and just in tears...

Has anyone else had similar experiences around the same weeks as I am currently...?