Withdrawal during pregnancy

Is it normal not to want to be around people during pregnancy? I feel like it has become harder to talk to people or even look them in the eyes. I am almost 5 weeks, so still very early. When I am around people for a long time I start to get moody and short. My mood swings do NOT help either. Has anybody else felt this way? I feel bad because I am often mean to people, and I know I'm doing it but I can't stop. I just want to be alone. :-\