Anyone know where i can find the mod for visitors to get pregant?
You don't need a mod as visitors can already get pregnant. If you're impregnating townies though, then only playing them can complete their pregnancy to delivery, otherwise, they would be doomed to be forever pregnant.
Visitors can only be impregnated if they are being played. To do this you can turn on testing cheats*, shift+click the sim you want to get pregnant and choose 'make selectable'. Their portrait will appear on the UI along with the rest of the household and you'll be able to try for baby with them. When you're done shift+click them again and choose 'make unselectable'. As JRD7 said, though, if you want the pregnancy to progress then you need to play that sim, otherwise they are stuck in limbo like the rest of the neighbourhood.
* Open the cheat bar with shift+ctrl+c and enter "boolprop testingcheatsenabled true" (without quotation marks). When you're done make sure you turn this off by entering the same cheat but put "false" instead of "true" at the end. If you don't turn it off you can get some strange game behaviour.
el flel thanks , i use inge teleporter the white cat, which have the same options, then i make them selectable so i hear the pregnancy music then later i play other family and move the townie thinking shes's pregnant but then she's not... im playing with a romance sim and i want to him impregnate most of townies i heard someone saying there's a mod for it.
I guess you can't impregnate townies then because they don't live in the neighbourhood and thus there is no way for the pregnancy to progress. You could move in said townie, try for baby, and then move her out into a house.
ACR also has an adjuster for the odds of woohoo resulting in pregnancy, so you could pretty much guarantee that every time woohoo happens, the ladies will be throwing up in your toilet before they leave.
As soon as the deed is done, you can adjust the odds back down again.