Any breastfeeding mamas ttc #2?

Jenna
I am currently BFing my 13 month old and have been ttc for 6 months or so. AF only returned last month and was 4 days long. I had been doing opks since 2 days after bleeding. Got what to me looks like a positive opk on 10/3 but still haven't seen AF and keep getting BFN. Am I loosing my mind or has anyone had really long weird cycles while nursing? I'm on CD 35...
I'm adding my opk from 10/3 for opinions (just now taking the picture and it has faded a little)