-You can file H4 petition now or just go outside US to get an h4 visa anytime (before or after I-485 denial).
By the way, it does not mean your I-485 will be denied. As long as you can find a job in the same/similar area, you will be OK if your current I-485 pending > 180 days. You may just use EAD to work so that you do not need to file H4 petition before your I-485 is denied (if any).
什么时候申请比较好,是现在,还是在移民局拒了我的485以后?
万分感谢!