Fertility Friend works out these details - but thats using temps. I think there is also mymonthlycycles and ovusoft (most have a free trial, and I think I have tried most of them). Hope you find one you like, my answer would be to try them all
I did have a really good one but the website no long seems to be there. The only other one i can reccomend is FF. You dont need to use temps with it (i just use mine for counting days now) but using temps helps determine your LP and the chart "learns" as you enter data.