pregnancy lactation breastfeeding current test positive women testing time standards 
childbearing potential pregnancy test negative female serum females urine prior 
protein urine ratio mg hour serum light dl proteinuria chain 
test pregnancy negative urine serum positive female hours confirmed study 
bearing child potential pregnancy test women negative pregnant serum female 
women pregnancy test childbearing negative potential serum days prior urine 
hcg chorionic gonadotropin beta human test pregnancy negative women potential