how long should a lawyer take before he tells you that you need a employment lawyer

There is no exact timeline, as workers compensation is typically your exclusive remedy unless there was additional negligence by a third party or the employer didn't have insurance coverage. Sometimes it's immediately apparent based on the facts, sometimes it can take months to find out there is no coverage. It all really depends on far more details that you will need to discuss with a attorney in detail. If you aren't happy with your work comp attorney you can always switch to a new one with no increase in fees. We all give free consults and take cases all over California