The Truth About Sexual Positions and Getting Pregnant. Share on Pretty pregnant woman timing contaction pains Your Best Days for Making a Baby · _top. Top tips and tricks for how to get pregnant, including when to have sex and the This means that the best sex positions for getting pregnant involve deep penetration. Well, apparently the sperm will pass through the woman's more acidic. (That said, we're guessing it's probably among the most popular sex positions to conceive baby.) “In woman-on-top positions, the sperm has to swim upstream.