The speaker remembers a small moment from the past: walking across a campus on a warm day and seeing words on a sign that another person was wearing. Those words reach "a hungry place inside" her, suggesting a loneliness or longing she hadn't fully named. The bracketed lines catch the moment of realization. She stops tearing leaves, a nervous habit, and the other person touches her hand and says "yes." It's a quiet, almost shy exchange.
Then the poem jumps three years ahead. The two of them lie side by side, and the speaker is pregnant, feeling the child "wiggling inside me." The jump skips everything in between, which makes the change feel sudden and wonderful.
The mood is tender, grateful, and a little amazed. The short, plain lines feel like a whispered thought. The ending, "miracles. / alla time, miracles," has a relaxed, almost musical rhythm, as if the speaker sees wonder in everyday life.