Pulling out

So, my husband and I lost our first pregnancy back in oct. 2015. We had a hard time with it, as to be expected, but I think we are moving forward. We are having unprotected sex and agreed on "if it happends it happends", he doesn't want the pressure of "trying" and failing. But I want to be pregnant again. We had sex during my fertile window and when I was ovulating last week. I am now in week one into the TWW. Last night we had sex and he pulled out to let go on my chest (TMI). I was thinking like wth? Why would he do that? I didn't ask but now I don't know what to think. Has this happened to anyone and got the guys opinion on why he did it?