Mods: Risky Woohoo by scarletqueenkat from Mod The Sims
Woohoo safely no longer!! Now when your sims woohoo there will be a chance of pregnancy! ALL woohoo spots are included.
I did test this very thoroughly with a risky chance set to 100%, neither Elders nor Teens got pregnant. After 5 days of the initial Woohoo/Mess Around, Elders and Teens still never had any babies.