In some aspects, the present disclosure relates to a lateral flow test device, a kit or an instrument comprising the test device, and a method of using the test device, kit, or instrument for quantitatively detecting an analyte in a saliva sample, e.g., a saliva sample from a subject, for example, for assessing hormone(s), ovulation, pregnancy, and/or fertility for a user, e.g., hormonal, ovulation, pregnancy, fertility status, time window, trend, or therapy monitoring or guidance for the user.
