There is no conclusive scientific evidence that any particular sexual position will be more likely to help you to conceive a baby. Despite this, it is commonly believed that those positions which allow the sperm to be delivered close to the top of the cervix may be more successful.
If this is so then having the man on top (missionary position) would offer the greatest possibility of conception. In this position the degree of penetration allows the sperm to be deposited high up the cervix.
Other recommended positions that allow deeper penetration are: from behind (doggy style), on-the-edge (the woman lies on edge of the bed and her partner can then enter from a standing or kneeling position) and 'scissors' (like two pairs of scissors at right-angles).
Having sex every two or three days throughout the month will give you the best chance of getting pregnant as this will mean you will have had sex around the time of ovulation which is key to your success. Any couple trying unsuccessfully to conceive for more than twelve months should consider asking to be referred to a consultant.
Female orgasm isn't necessary for successful conception, but the contractions experienced during orgasm could help the sperm to move up towards the uterus. It is also thought that remaining lying down for at least 15 minutes after sex gives the sperm more chance of remaining in the vagina and reaching its target. There’s no harm in trying it.