Ovulation predictor apps-HELP!!

Courtney • 28 yo just married my best friend and high school sweetheart! Ready to have a baby!!! Or two or three;)
I am getting different expected ovulation dates between a couple different apps...?!? How do I know which one is right? I have a feeling this has been the problem so far. AF started on 10/17. My avg cycle is 32 days---- This month I will try OPKs- I bought Answers brand-hope they work well! Any suggestions would be appreciated :)
​Thanks