At three months, many women find the unpleasant physical reminders of pregnancy (the constant tiredness and ravages of morning sickness) begin to lessen, and although they haven't begun to "show," their jeans are feeling a little snug. (Women with second or third babies often begin to show earlier than first timers.)
By the third month you're also likely to be tiring of the sort of limbo you've been in when it comes to receiving sympathy and help. During the first trimester you have felt pregnant - tired, nauseated, grouchy, short-tempered, and generally on an emotional roller coaster - even though your body has not yet revealed what's going on inside. Accordingly, many friends, relatives, and especially your spouse may not have been offering you either the sympathy you want or the help you need.