You indicated that the object is moving with constant speed when it is at point A.

The circles in the motion diagram above are the trail markers that illustrate the path of the charged object that is moving through the electric and magnetic fields.  The time interval between successive trail markers is always the same.  An object that is moving fast travels farther during one time interval than an object that is moving slow. 

Speeding up simply means that the speed is changing from slow to fast.  Conversely, slowing down means that the speed changes from fast to slow.  An object moving with constant speed is moving with a speed that is not changing.

If the object really is moving with constant speed at point A, then the speed at point A must be the same as the speed at a point near point A.  Is it really true that the speed at point A is the same as the speed at a point just before or just after point A?