Calendar method

Flo app ginamit ko calendar method, 3months before umuwi si hubby from abroad nag input na ko ng record to track kung accurate. And yes accurate sya, makikita mo kelan ka fertile. After 3months tracking, pinili ni hubby flight na same sa date na fertile ako sa app. Ayun, pregnant na ko the next month. So I say, yes safe and accyrate gamit as calendar method si Flo App.