52 day cycle

Raegan • This skin and bones is a rental.
I usually have a 52 day cycle, almost like clockwork, and now I'm currently 18 days late (currently on CD 70). All HPT's show negative.  I called my Dr's office & the nurse advised me to come in Sept. 1 if I still don't have a period by then. I'm not on birth control because my hubby and I want kids someday (sooner rather than later, though not actively TTC), and don't really think adding hormones to my already whacky body is a good idea. I'm afraid we have a long journey ahead of us, as my dr. all but told me I will have trouble conceiving. 😕
I believe God is the giver of Life & could give us a baby whenever He chooses, but I am doing some research. Just wondering if anyone else has painfully long and unpredictable cycles? If so, how do you monitor ovulation? Have you been able to  get pregnant? Any info would be of great use to me. Thanks in advance!