Pip assessment phone call

Hi I have my phone assessment tomorrow really anxious and getting nervous. As have some bad experiences in previous ones. My question is that I received a call about 3pm today from the assessment centre which I didn’t answer but rang back as they had left message. So thought it must be important they asked me security questions then said were just ringing to make sure I was ok for the important tomorrow and if I had received the letter if I hadn’t she said you can ring our customers services number and said if I could write it down. Is this normal practice or do you think they were trying to catch me out as last time on my assessment she asked me to sign my name and because I did they said I could drive a car, cook , Bath, dress, manage medication. Or do they usually ring day before. Thanks I’m so nervous now as paranoid all the time they are trying to catch you out. I suffer with bad Fibro/ arthritis and depression.