You have the timing right, you're in the mood and you finally get around to doing the business.
But what's the best way to make love to get pregnant - up against a wall, or in the missionary position?
Follow our light-hearted guide to baby-making sex below.
Let gravity do the work
Making sure your partner's sperm is as close to your cervix (neck of your uterus/womb) as possible is vital for fertilisation. Getting sperm to swim up your Fallopian tubes is the key, so help them by letting gravity do some of the work; either by lifting your legs up in the air, or leaning them against the wall. You could also try lying on your back in the missionary position with a pillow underneath your hips to give you an extra lift.
Be a missionary
It might seem like the boring way to get intimate, but the missionary position, with all that deep penetration close to your cervix, is going to give your partner's sperm a little extra help in their swim for the egg!
Stay in bed
Don't leap out of bed and go straight to an aerobics class after sex. If you want to get pregnant, lie on your side and draw your knees into your stomach. Get your partner to bring you some croissants and coffee in bed, and don't forget to take a pre-pregnancy folic acid tablet with some orange juice. Stick a pillow under your hips, put your feet against the headboard, and relax for a while. Try to visualise your body making miracles.
Have an orgasm
As well as bringing a smile to your face, good sex makes babies! It's official: a post-coital study of women found that those who had orgasms and enjoyed their sex retained more sperm than those didn't. It's all to do with the muscular contractions you experience during an orgasm, which sucks up more sperm.
Do your pelvic floor exercises
Strong pelvic floor muscles. They're good for you, they're good for him, and they're good for making babies! We don't know for sure, but a few pulls in and up after sex can't do any harm, can it?
WATCH: Around the House Sex Positions Attempted by Real People. Continues after video ...
Doing it doggy-style is guaranteed to get your partner's sperm close to that all-important baby-making organ - the cervix.
You don't want to do it like that!
Get off him! You don't want to be on top when he lets loose, as all his sperm will come rushing back down again. By all means, do it this way before he comes, but when you know it's getting serious roll over!