52 days between AF's???

Laurie • I am 34 years old and have a 6 year old daughter. TTC #2 since 4/14
34 y/o TTC #2 daughter is almost 6. Stopped Nuvaring late April. Had AF from 5/4-5/8. Just now having AF again but very light. 52 days with no AF and many BFN. Is this a real period?  How do I know when to start an opk? No probs first time so all this is so confusing! HELP!