A
beta hCG falling from 187 to 131.77 in 48 hours means it is not rising the way it should in a progressing pregnancy, which normally roughly doubles in that window at this range. This points toward a pregnancy that is not continuing, though your doctor also needs to rule out an ectopic pregnancy, especially since you have no bleeding yet and the pregnancy's location has not been scan confirmed. Your 2020 missed abortion does not predict this outcome; each pregnancy is judged on its own numbers and scan findings.
Next Steps
Get a repeat
beta hCG and a transvaginal ultrasound in person today rather than waiting, so the location and viability can be confirmed directly.
Health Tips
If one sided abdominal pain, dizziness, or bleeding start before your appointment, treat it as an emergency. Please consult your gynaecologist urgently.