question

ok ladies my soon to be hubby bought me presseed and bbt thermonater and opks tests I was wondering when should I use the preseed and wondering when should I use the opks and if any one can help me figure out how long my lutheal phase is my last few periods were last month 13 Thur the 17 and then April was 5 Thur the 8 and then the 30 and tht is supposed to be until the 4 can anyone help me out and give me advice and how does the chart actually work is it when I get a really high temp does the mean I'm ovulating also and can y'all help me figure out when I'm actually gonna be ovulating also I was told to use the preseed through out my whole fertile week and on the day I have the big o any thoughts or suggestions will be greatly appreciated tia