I calculated from my pay stubs that I should have, say $1000 from Jan 1 to Mar 31 and my employers contribution was $800. But on my 401k statement it says that I only have $600 from my contributions and my employer contributed only $90.
On your contributions, are you taking into account that the value of your investments almost certainly declined until the past few weeks? On the employer's contributions, the Plan Document probably gives them a goodly period of time to make those contributions. They can lag behind for many months.
A couple of suggestions:
1) Stop by your HR/benefits person and have them explain your 401(k) statement to you. Or contact the Plan Administrator and ask them to do so.
2) If you think there is a discrepancy between what you contributed and what's showing up on the statement, ask about that as well.
3) Also inquire about the timing of the company's contributions - how long they have to make them under the terms of the 401(k) Plan and how current they are
4) Ask HR or the Investment Advisor for a copy of the Summary Plan Description (SPD) of the 401(k) Plan. That should answer some of your questions as well.