As summer vacation begins, 17 girls at Gloucester High School are expecting babies — more than four times the number of pregnancies the 1,200-student school had last year. [...] All it took was a few simple questions before nearly half the expecting students, none older than 16, confessed to making a pact to get pregnant and raise their babies together. Then the story got worse. “We found out one of the fathers is a 24-year-old homeless guy,” the principal says, shaking his head.