I am 39 and 6 weeks preg, hcg 6900 and progesterone level was 4.4 ng/ml .i started prometrium (micronized progesterone) 200mg vaginally bid .is there any hope of a viable fetus?

Yes: Yes, there is hope. Keep using the Prometrium (micronized progesterone) as directed.

Ultrasound: At an HCG level such as you describe, there should definitely be something able to be seen inside the uterus that would answer this question. I suggest that you consult your obstetrician and ask for an ultrasound to determine pregnancy dates and progress.