Hello there,
I work in a fertility lab and this is (believe it or not) a fairly common question. While I can offer advise, it is best to talk to your OBGYN or a reproductive endocrinologist for a proper work up. There could be hundreds of reasons why you haven't conceived-as a regular period does't indicate that you have open fallopian tubes or normal hormonal levels. But the fact that your fiancee has an inguinal hernia MAY or MAY NOT indicate that he has a condition known as Antisperm Antibodies. This condition occurs in men that have had either an injury or illness that breaks the "seminal fluid/blood barrier". Believe it or not, sperm is actually considered a "foreign antigen" in a mans body, sperm is confined to the testicular region-hanging outside the body. An injury that breaks the blood/semen barrier can cause the mans blood to see the sperm as foreign and actually make antibodies against it. (As happens when you're exposed to other antigens, like chicken pox) The antibodies then cause the sperm to clump together, rather than allowing them to swim in a rapid forward motion. The great news is that this condition is completely treatable with minor intervention-like a sperm "wash" with IUI (insemination performed in a doctors office) the "washing" is just taking his ejaculate, mixing it with some antibiotic medium and centrifuging it to "clean out" some of the antibodies, if present. This can be done at a doctors office if testing shows that he does in fact have this condition. Again there are many other reasons for infertility, this being just one of them. If you are not ready to seek medical advise, it is a good idea to invest in some ovulation predictor kits and have intercourse during the time of ovulation. Good luck to you both!