Haven't had sex :(

I'm 5 months and my bf and I haven't had sex in 2 months and it's not that I don't want to I actually do he just hasn't tried or I guess doesn't want to :/ I feel weird even having to ask him why I don't wanna beg for it it makes me think so many thing maybe it's because I'm fat or he's not attracted to me or maybe he's having sex with someone else? Don't guys always wanna have sex? It seems odd and it's making me think too much...what should I do?