A lateral flow assay strip comprising: one or more chromatographic substrates; a sample application site on each chromatographic substrate for application of a portion of a liquid sample; a first capture site disposed on a first chromatographic substrate, the first capture site being spaced apart from the application site such that when the liquid sample is applied to the sample application site the liquid sample moves through the first chromatographic substrate from the sample application site to the first capture site, the first capture site comprising an anti- human chorionic gonadotropin ('hCG') capture antibody with broad affinity for a group of multiple hCG variants, the presence of the group of hCG variants in the liquid sample being indicated at the first capture site by the presence of a first detectable signal caused by the presence of sandwich complexes at the first capture site; and a second capture site disposed on the first chromatographic substrate or a second chromatographic substrate, the second capture site being spaced apart from the sample application site such that when the liquid sample is applied to the sample application site, the liquid sample moves through the first chromatographic substrate or a second chromatographic substrate from the sample application site to the second capture site, the second capture site comprising an anti-hCG capture antibody that is specific to a first variant of hCG, the presence of the first variant of hCG in the liquid sample being indicated at the second capture site by the presence of a second detectable signal caused by the presence of the sandwich complexes at the second capture site. one or more chromatographic substrates; a sample application site on each chromatographic substrate for application of a portion of a liquid sample; a first capture site disposed on a first chromatographic substrate, the first capture site being spaced apart from the application site such that when the liquid sample is applied to the sample application site the liquid sample moves through the first chromatographic substrate from the sample application site to the first capture site, the first capture site comprising an anti- human chorionic gonadotropin ('hCG') capture antibody with broad affinity for a group of multiple hCG variants, the presence of the group of hCG variants in the liquid sample being indicated at the first capture site by the presence of a first detectable signal caused by the presence of sandwich complexes at the first capture site; and a second capture site disposed on the first chromatographic substrate or a second chromatographic substrate, the second capture site being spaced apart from the sample application site such that when the liquid sample is applied to the sample application site, the liquid sample moves through the first chromatographic substrate or a second chromatographic substrate from the sample application site to the second capture site, the second capture site comprising an anti-hCG capture antibody that is specific to a first variant of hCG, the presence of the first variant of hCG in the liquid sample being indicated at the second capture site by the presence of a second detectable signal caused by the presence of the sandwich complexes at the second capture site.