If you have been trying to conceive for more than a year without success, you can ask for medical help. it doesn't seem that taking vitamins or using certain position during sex can help you to conceive if you or your partner is experiencing a reproductive disorder. To confirm or reject this possibility, first your partner can request a sperm investigation (spermogram). If everything is OK, your turn is next. Investigating sterility in women is more complicated than in men because several diagnostic procedures are included: vaginal examination, colposcopy, Pap-test, tests for STD, vaginal ultrasound, hormonal analyses, HSG, uteroscopy and laparoscopy. Treatment depends upon the diagnosis. You can consult your gynecologist for more information and to follow up.