sevis变了 签证没过期

我8月份毕业回国 然后申请了我们学校的研究生 因为我离开超过五个月了 老师说要重新给我一个SEVIS，我要重新签证吗 我给老师发邮件老师又说不要 我怕在海关那被扣下 现在纠结中 请问到底要不要呢? 这个是老师回我的The fact that you will be gone more than 5 months changes things. We will have to issue an initial I-20 with a new SEVIS number. You will have to pay the SEVIS fee again. But if your F1 visa is not expired by the time you enter the US with your new I-20, then you do not need to get a new visa.