Help! 2 years TTC.

Husband sperm test was perfect. 28 day cycle. Ovulate on day 14. Like the book since I was 12 years old. BUT Recently over last 6 months, cycles are anywhere from 25 days to 31 days. This month ovulated on day 13.  Vaginal and abdominal ultrasound show everything is perfect. Blood flow is perfect to ovaries.  Ultrasound showed I was ovulating that day even. NOTHING. What am I missing? Only thing I don't know is the shape of my uterus or condition of Fallopian tubes (those tests are more expensive--insurance doesn't cover infertility). Have appt w new doctor April 13, but I need advice until then? Anything?