Help! Cycle day 40, no confirmed ovulation

Tia • Ttc our rainbow baby since June 2014
I'm currently on cycle day 40 and my bbt still hasn't shown a thermal shift to confirm ovulation. This is my first cycle trying opks and they've all been negative too. Last cycle my O wasn't confirmed by bbt until day 61. Has anyone else experienced something like this? Any advice on what I can do? Any help would be greatly appreciated!