The invention relates to a method for predicting and testing physiological conditions of a female mammal related to an increased level of ferning present in a dried mucous body fluid sample of the female mammal, comprising: capturing an image of the dried mucous body fluid sample via a camera of a mobile telecommunication device through a magnifying lens releasably coupled to an objective of the camera, detecting the presence of crystals in the sample by processing the image, determining the crystal density within the sample from the detected crystals, predicting the physiological condition of the female mammal by comparing the crystal density to reference crystal density data, wherein increased crystal density is indicative of increased ferning level. The invention further relates to a mobile telecommunication device comprising: at least one processing unit, a user input interface, a display, a camera having an objective, a magnifying lens releasably coupled to the objective, at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processing unit, cause the device to perform at least the following: capture an image of a dried mucous body fluid sample of a female mammal via the camera through the magnifying lens, detect the presence of crystals in the sample by processing the image, determine crystal density within the sample from the detected crystals, predict a physiological condition of the female mammal related to an increased level of an ferning by comparing the crystal density to at least one reference density, wherein increased crystal density is indicative of increased ferning level.