What are the chances that this pregnancy is viable.

Hello, I am 6 weeks 2 days pregnant from my 2nd FET, we transfered 2 good quality 5 day blasts on June 13th. Yesterday I woke up bleeding, it was about as heavy as day 3 of my period. It only lasted a couple of hours but it did contain some clots. I went to the clinic and they repeated my HCG, on July 1st it was 1600 and yesterday July 7th it was 5000. From what I read when you are over 1200 your doubling time is 3-4 days. I go in tomorrow for a repeat HCG but am going crazy in the mean time so looking for your opinion.

Thank you