As long as it doesn't get direct sun it should be happy there, just don't let it touch the glass, a sheer curtain would be good once summer gets here.
A picture of the whole plant and ideally plant tag would help you get better advice.
If you bought the plant on Jan 6th it could have been in bloom for weeks already so it was probably ready to loose its blooms.
A picture of the window and radiator would be helpful also.