i had been taking my temperature for a yr & a half , you start taking your temp the 1st day of your peroid as it will be quite low untill you ovulate then it will rise , & if you fall pregnant your temp will stay high but if not your temp will drop down again before your peroid starts , you could try a website that i used & im still on it now as there is some nice people on there & if you plot your temp on there everyday it will tell you when you have ovulated it even gives you tests days that it thinks you should test if your peroid dosen,t turn up , a digital one is fine as thats what i used the website is called ,
www.fertilityfriend.co.uk
(26 months ttc till i got my bfp since coming of depo )