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My wife informed me that the morning after pill is not taken AFTER pregnancy test, and only immediately after intercourse. Disregard what i said about the pregnancy test part. Still though, don't do it. it's stupid. Just wait
*edit*
So what's the plan? You are going have her take a morning after pill after every time you have sex? Or you are going to do a pregnancy test every single time after you have sex and then take the pill if it's positive? What if she changes her mind suddenly and decides she doesn't want to get rid of it? Wouldn't it be easier, cheaper and less side effects to just use a condom? The morning after pill can cause nausea, vomiting, breast tenderness, changes in period timing and flow, headache etc.
Think this through really carefully dude, you don't want to get stuck with a kid you don't want because your woman decides she actually can't go through with taking the pill. I know you are going to say "she wouldn't do that to me!!"... Trust me when I say a lot of men before you thought the same thing and wound up getting burnt. There is a shitload of potential risk for very little payoff when compared to simply using a condom...
If you guys allergic to latex there is also sheep skin available.