Hi, My Name Is Melecia. I Need Some Advice. I

hi, my name is melecia. I need some advice. I was tested to be pregnant. had an ultrasound done and they did not see anything. My doctor said my hcg level is around 2000 and that they should be able to see something, a sac or a pole but they didnt see this on the scans. The doctor also showed my fallopian tubes which is clear of ectopic pregnancy. But yet they want me to take a medication to end whatever is growing that is causing my hcg levels to rise. I want to wait longer for another scan but they say this is dangerous and i need immediate medication. does this sound like a worthy ectopic pregnancy? Rising levels, no tubal pregnancy, but no evidence of a sac or baby at 5-6 weeks 2000 hcg levels?