Rapid Response hCG Strip Pregnancy Test HCG-1S50. For early detection of human chorionic gonadotropin in human urine. Overall accuracy greater than 99%. Standardized with WHO international reference standard. Sensitivity of 20 mIU/mL - detects pregnancy as early as 7 days after conception. 100% specificity - no cross reaction with FSH, LH or TSH. CLIA Waived. CPT Code 81025. 50/BX. Priced per box.