Ovulation whats going on!!!!

Ok so I have a few different apps on my phone tto let me know when i should be ovuating. Im not the normal 28day I am more like 35-37days. All of the apps give me different ovulation days. One said the 17th ok had intercourse that day. Another said 20 yes we did the do again. The other I have says 24th i will be. I didn't take a opk so wasn't sure if I ovulated or not. I know they say there is a change in CM ... But I have none. Just hoping hoping hoping this month is our month.