The 4-6 weeks after switching jobs are when you will most likely think that you made a mistake.
Shortly after starting a new job, it isn't out of the ordinary to start wondering if you made a mistake by leaving your previous employer and / or joining your new employer.
You might feel that the new company is not what you thought it would be, you might feel that your new job is not as it was described or it could be something else that leads you believe that changing jobs was not as smart a decision as you thought it was when you were signing the job offer.
You might forget why you were so happy to leave your old employer in the first place!
I've seen situations where a company was so eager to hire someone – especially situations where it's a newly created job – that they don't actually have much work for the person to do when they start.
I know one fellow whose new company did not have a desk for him when he joined his new employer.
They'd forgotten to figure out where he'd be sitting!
Certainly, it's not a good situation when you start a new job and get the impression that the company did not even realize you were being hired.
The important thing is to remember why you left your old job. Before you start wishing you were still with your previous employer, think of the reasons why you chose to leave.
Then think about exactly what is making you feel your new job is not what you expected and try to figure out how you can improve you situation.
Before you talk to your manager and spill your guts, really think about how it could look if you tell him / her that things aren't what you expected.
Often, it can take several months before you really get to experience everything that your new job and company has to offer.
If you have switched jobs recently, don't give up on your new employer too quickly.
What you might consider doing is waiting for several days before acting on any hunch that you have to ensure that the feeling does not pass. Perhaps you are just over analyzing the situation.
If the feeling persists, you might consider meeting with your manager for a few minutes but rather than complaining, ask your manager how he / she feels about your performance so far and what they have planned for you in the near future ie. what work will be you be doing next?
Basically, put the situation in their lap and ask for some initial feedback. Often you'll find that they discuss things that might help to explain your feelings of regret and might help to shed light on why things have gone the way they've gone so far.
Your manager and / or the company in general might have things going on behind the scenes that you aren't yet aware of that could help explain why your initial tenure with the company has been a disappointment.
This could be especially true if you were brought on board to fill a need that was pending and hasn't quite come to fruition yet. Perhaps the work you were brought on board to do is imminent but the timing just hasn't worked out exactly as initially planned.
What you don't want to do is start pondering the idea of approaching your old employer and seeing if you can return. The natural reaction for some people is to think about the possibility of rejoining their old firm, perhaps where it was more comfortable and where things "suddenly don't seem so bad afterall."
Always remember to look forward not backwards when considering your career. Again, think about the reasons you started looking for a new job and ended up accepting it in the first place.
Chances are that your new position will amount to what you thought it would if you did your homework before accepting their offer. The first few months in your new job requires a lot of unheaval and change so just remember to give things enough time.
If that doesn't help, think about this story. A friend of mine once quit his job after accepting a new position elsewhere and then took two weeks holiday out of the country before starting the new job.
When he walked into the new company on his first day in his new job, he was immediately told that the company had restructured while he was on holiday … and that his job had been eliminated!
He started and finished his new job on the same day.
Now, that's something to have second thoughts about.