I am 48 years old, and am now experiencing the so-called perimenopause. I had hot flashes, nigh sweat, insomnia and all others. My most recent problem was I had a flow, which lasted for almost 17 days and required me to change hourly. When I calculated for the cycle, how will I count the days? Shall I start counting four weeks ahead from the first day? Or shall I just guess my estimates for my cycle? I want to know as having this kind of perimenopause period hassles planning for an intimate weekend.