This means that if a woman has a 28 day cycle from the start of one menses to the start of another, she will probably ovulate on day 14 after the start of a menses. If a woman's menses came every 32 days, everything would shift by 4 days so that ovulation would be day 18 and the range might be day 15-21. if you are having intercourse only once during that time frame, it will be more difficult to conceive. The tubes must be free to sweep up an egg that has been ovulated from the ovary and then it must not have any blockage to passage for the egg, the sperm or the fertilized egg. Fertilization usually takes place in the faloppian tube close to mid way from the ovary to the uterus. Pelvic surgery, past ruptured ovarian cysts, past pelvic infection and endometriosis can affect the ability of the tube to sweep up the egg.
Pelvic infection can also produce scarring inside the tube that prevents passageway of an ovum.
The way to determine that is to have an xray of the uterus in which a dye or other substance is injected into the uterus and then an xray or ultrasound is used to see if the dye goes through the tubes into the pelvic cavity where the ovaries are. If the dye spills, then the tubes are open enough to allow pregnancy. You need to have this study done because if the tubes are not patent, all of the other treatment for your husband's sperm problem will not have any use for natural conception. Blocked tubes may be a reason to have in vitro fertilization however. Uterine factor - successful implantation of the conceptus Any condition that alters the amount or shape of the surface area of the inside of the uterus or alters the hormonal readiness of the lining of the uterus may impair fertility.