Only 5 + 3

So I'm 5 weeks and 3 days and none of my clothes fit :( I don't want to get maternity clothes yet I'm barely even pregnant. When did you guys have to start getting maternity clothes? I feel SO HUGE I know I'm not "showing" but part of me is wondering if 1) I'm having twins or 2) if I'm further along then what we had thought.... I'm just very very uncomfortable :(