Hi, I understand your concern. Menopause is a prolonged process- it s duration being varied person to person. The basic cause is withdrawal of female hormone estrogen, The fall is gradual & fluctuating , creats all the symptoms of menopause like- - Hot flushes, palpitation, irregular periods - Thinning/drying of vaginal skin, itching,vaginal infections, - osteoporosis -joint /back pains - dry & less elastic skin, breast atrophy - psychological irritability/depression The symptoms start with fluctuation of estrogen ,so in peri menopausal stage estrogen may be found in-spite of the symptoms. Thanks.