HCG rise slows down but healthy pregnancy anyone? Please love to hear your story.

Anyone experienced sudden slow in HCG rise?? 18DPO (4 wks 3 days) 764 20 DPO (4 wks 5 days) 1989 24DPO (5 wks 3 days) Started spotting then bright red bleeding, no clots no pain. Bleeding stopped that night. 25DPO Brown spotting. sac seen on ultrasound along with subchorionic haematoma. 25DPO (5 weeks 4 days): 8,453 27DPO (5 wks 6 days): 10,624 Between 25 and 27 only 25% increase? Chances of a viable pregnancy? Ultrasound booked for 7 weeks, and another HCG draw in one week.