I also did not have my period for 2 months and I went to my OBGYN. She gave me...I forget the name, but it was a pill I took for five days. After the 5th day, I got AF. She told me it would help put my cycles back on track. Maybe, it's something you can try.
I have never done the temps before, but I'm thinking I should b/c it doesn't seem like I ovulate often. I've taken the OPKs and they are always Neg.
My doc says she could start me on Clomid to help me be able to tell.
I would go to your Doc and he/she may be able to shed light or help you out.
(I heard you could still be ovulating even if your AF doesn't come, but not usually. I wouldn't start temps until AF comes.)