seriously?

I am 32 weeks pregnant and dying of heat i asked my boyfriend if we could go to the beach along with his sister to join us but nooooooooo! he said he didnt feel like driving anywheres today so we are sitting at home me & him and then he gets a text from this girl asking if he wanted to go with her to the beach he got up in 2 seconds and left for the beach! what the heck is going on? What in the f do i do? I am carrying his child & he does this to me? im so confused does this mean something :/