need help!!!

I am in Canada now, I want to apply for US J1 visa, becaue the starting date in DS 2019 is coming soon. But my current canadian work pertmit expired and I have applied for the new one. Now it will take several months to get it, I called the immigration officer in Albert and they told me I can work at the same place until get the new one. So I want to ask could I apply for J1 visa without a valid work permit,and just show the Visa officer my boss' letter for my work permit renewal. Is it a serious problem and I will be denied? I really appreciate it if somebody had the same situation can give me an answer.