Im so confused!

I am about 5 weeks pregnant an i have found my boyfriends adopted son is annoying the crap out of me. He an i usually get along really well with no issues. But for like the last month i cant even be in the same room with him if i hear him talking i am instantly annoyed an his presence just drives me insane! Please tell me its just hormones an will pass i feel horrible because he is a nice kid but right now i kinda wanna strangle him. Anybody else have this problem?