Hcg levels not doubling

So I've had my blood tested three times now. First was 92, then 4 days letter 229, and 4 days later 483. My levels are rising but not doubling every 48 hours. Basically, the nurse told me I'm going to miscarry, I have an ectopic pregnancy, or a very very slim chance I am actually pregnant.  Anyone else have similar results? If we go based on the 72 hour rule I am in fact doubling but apparently that doesn't count.