first time OPT 00xxx timeline

根据USCIS account里的显示，
2/13 case was received
4/12 We are producing your card and will mail it to you
case status网站依然只显示2/7 case was received

补充内容 (2018-4-19 01:14):
4/16收到纸质approval notice
4/17状态更新为We mailed your card to you
case status网站依然未更新。

补充内容 (2018-4-20 00:50):
今天case status更新了直接是card was mailed