Thanks for your query.
LH surge is indicative of ovulation, but that does not necessarily result in a conception.
Having delayed and irregular periods
is a sign that you might need help in regulating periods and also in conceiving.
Just relying on progesterone
measurement is not enough.
Please consult an Infertility
specialist and have thorough evaluation for irregular cycles as well as for difficulty in conceiving.
Anxiety, stress, ingestion of medications, being on birth control, hectic travelling, changes in weight , recent illness or fever - all are reasons of irregular cycles.
Thyroid hormone disturbance, adrenal dysfunction, high prolactin
levels, polycystic ovaries
, endometrial pathology - all can cause such problems.
I would urge you to get professional help at the earliest.