Have you had all of the following tests? If not, why not?
Semen analysis (repeat semen analysis if abnormal in any way) to include testing for antisperm antibodies.
Blood tests for FSH, LH, prolactin, testosterone and thyroid tests (during day 1 to 5 of menses).
Blood test for progesterone (day 21 to 23 of your cycle).
Vaginal ultrasound scan in a natural cycle between day 10 and 14 of menses.
Post coital test timed accurately with ultrasound or urine testing.
Laparoscopy and dye test (HSG, if laparoscopy inconclusive).
Hysteroscopy: preferably at the time of laparoscopy between day 5 and 10 of menses.
Endometrial biopsy: Where a sample is taken from inside the womb, to check for normal development of the womb lining. This test should ideally be performed after accurate ovulation timing, between day 4 and 7 post ovulation.
Doppler ultrasound studies of the uterus; to check for normal blood flow responses of the uterus in your natural ovulation cycle. 50% of women who have failed to conceive despite 3 or more IVF attempts, have poor uterine blood flow.
Blood tests for antisperm antibodies if the female partner has cervical hostility or if the male partner has had reversal of sterilisation or low sperm motility.