When we applied for my visa, my husband sent all the documents (including letter to the ECO) during the last week of October...
Had to wait for IELTS Result which is usually 13 days after the exam..
And had to find a suitable time to abandon the students...

So I lodged visa application on the 5th of December...
And it went all right - got my visa after 7 days..

Good luck.. You will be all right.