My married sims won't woohoo?

You have to use romantic actions until one of their chats says "[So and So] thinks [So and So] is being irresistible". Then it will pop up the options for Woo-Hoo and Try for Baby.

the peple is areter maed

Make them do romantic interactions until it says <Sim's name> thinks <Sim's name> is being extremely irrestable and the option should come up. Or, make them both relax on a bed and the option will be there. If you have the Late Night expansion pack, click on the shower or elevator and the option will be there. Another option is make them tour a building such as the city hall or military base and the option should be there. Btw, you need to do the "try for a baby" interaction to get pregnant. Hope I helped & good luck!

P.s. Sorry this is late.