ES+19 period is missing (5 days late, test negative)?

Hello everyone, My period is always on time. Today is 18 days past ovulation (4 days late) and I feel fine so far. No PMS, nothing. Occasional slight lower abdominal pain (very brief, 1 or 2 seconds). Six days after ovulation, I had a very light spotting (one small "bubble" in a protein-like cervix). Tested…