hCG Curve: Multi-Draw Trend
Three or more values, one fitted curve — because a trend line answers questions two points can't.
Early hCG changes exponentially, so the values are plotted on a logarithmic scale, where exponential growth becomes a straight line. The tool fits that line by least squares across all your draws and reports the overall doubling time (or half-life, if falling), the equivalent 48-hour change, and how consistently your points follow one trend (R²). A high R² means one steady process; scattered points can reflect different laboratories or assays — always trend values from the same lab when possible.
The fitted 48-hour change is interpreted against the same thresholds as the two-value calculator: Barnhart 2016 level-stratified minimums, the 35% floor, and NICE NG126. One honest caution: a single fitted line assumes one ongoing process. If your values rose and then fell, the last two points matter more than the average — the tool will tell you when that applies.