I dont understand why my husband is treating me weirdly during pregnancy

Im 15 weeks preg. And my husband has been weird since i finished the first trimester, it gets the weirdest when we have sex so i even regret it afterwards even though he likes it, when i ask him whats wrong he just blames the mood or the working long hours, but i started to feel lonely and depressed, i spend the whole time crying and alone, and i really dont know what to do, im terrible and terrified since i have no family members nor support system near me:(