Late opk

Hi ladies,

I normally have a reguar 35day cycled however this month my cycle is long all of a sudden. This is our second month ttc for baby#2 nd i received two 'peak' clearblue opks- one on cd18 and the other on cd35 last week when af was due. Pregnancy tests are negative. Im very confused as this has never happened before.

Have any of you ladies had a similar experience ?