Chanceit
I am not a returning social worker but I am aware of some
findings by the Care Standards Tribunal http://www.carestandardstribunal.gov.uk/
of some experiences of some social workers who were attempting to either
register for the first time (just qualified) or re-entering the profession
again, as you intend.
If you take a look at the Care Standards Tribunal website
(see link above) you can find all its findings on GSCC matters (and much more)
including some notable and concerning findings (e.g. http://www.carestandardstribunal.gov.uk/Public/View.aspx?ID=63
) which will be rightly of concern to
anyone. Probably, (one never really knows) most applications are fine and
trouble free, but it is rigorous (supposedly except when it comes to
investigations of complaints) and not exactly quick, at the best of times. If
there is significant delay in registering you (over three months) I would start
asking the GSCC what the problem is –you might find yourself being subject to
an investigation (as in the case matter in point, noted above) and not notified
of it or, probably more likely, some ‘dork’ at the GSCC not pushing paperwork
as it should be.
I wish you well 
Wilt