I think it is very unlikely we will go down but now is not the time for complacency. I think the assumption 50 points will be enough to stay up this season is not set in stone. Looking at fixtures remaining for teams lower in the table they could end up with the following points.
stoke
54
qpr
51
millwall
53
huddersfield
52
birmingham
53
I wont be happy until we have 3 more wins Cardiff Swansea and Plymouth hopefully. lose or draw those and pick up nothing from Ipswich West Brom and Leicester we are going to be very close to the bottom 3. in 2013 Peterborough went down with 53 points - the average for safety is 49.7.
Relegation for us is unlikely but lets wait till we have 55 points before we start crowing about relegating Stoke on the last day.