Hi I have just turned 48 and spotted when I went to the toilet 6 days before periods due. My periods have not come. Could I be pg?

Not likely, but. If you still have been ovulating, i guess it is not 100% impossible. It is far more likely that you are peri-menopausal and your periods will become irregular, scant and stop altogether over the next few years. If you wish, you might do a pregnancy test. If it is positive, definitely see a doctor as this might be considered a high-risk pregnancy due to your age. Good luck!