Low libido or uninterested?

I just dont want to have sex with my boyfriend. I’ve had a terrible low libido this pregnancy and now that I’m 30 weeks I’m exhausted and don’t want to be touched. We tried to have sex lastnight...well he tried touching me and started something but I legit felt weird..it felt like a stranger was touching me and when I told him no and we stopped I kinda started to cry. Before pregnancy we used to have sex like twice a day sometimes, but I’m scared now ... can I blame this on the pregnancy or am I just not interested in him :(