Low tax credit payment

I wonder if anyone can help me....

My husband started a new job in feb and I informed tax credits and my payment was reduced to about 400 Ish a month, I was also told I would need to call back on the 6th April and give his full annual figure for the tax year as they couldn't take this then, only the figure for the two months leading up to April and obviously his previous earnings for that tax year.

So anyway I called up and notified them that his annual income would be 16,640 ( I currently don't work as have a little one, so this is our only income.)

I have logged onto my bank acc this morning to see that this month we have only been paid £111.00 this month. I haven't had the paperwork through the post yet, so I can't check anything, but I didn't know if this is because I have been overpaid somehow ( no idea how as I have kept it all completely up to date) or is this what my payment will now be each month? I checked on the payment calculator thing and I thought we would be getting about 350 a month .

Can anyone shed any light on what's going on, as I now need to reassess our budgets eek!!

Thank you in advance