Am I miscarrying with flucuating hcg levels?

My lmp began on 10/31/12. I was on clomid from cd 5-9. I had a pos opk on 11/18/12. On 11/28/12 I ended up the in the er with a 3 day migraine and neck pain. They did a beta before an mri and it was 79. Then my ob did another beta on 12/3/12 and it was 73. Thought pretty certain it was another miscarriage(would be the 3rd). They wanted to repeat my numbers just to check. I went for a retest on 12/5/12 and it was in the 240s. I am so confused. They want me to continue progesterone suppositories and other stuff and they will reset on 12/8 . However I am very confused. I know there is a possibility of ectopic and vanishing twin syndrome. But my numbers nearly tripled in 2 days. Any in sight?
11/28 beta 79
12/3 beta 73
12/5 beta 240
12/8 next beta????

[Bkitty]

It could just be that the hosp lab and the lab that your doctors office use are different? This happened to me. You are supposed to double every 48hours and you did!! That's good! Unfortunatly for me Mine are not going up fast enough and Ive been told its only a matter of time. I hope the best for you!! Saying prayers ((hugs))~Bkitty