In theory every 3 months in practice dependant on your sugery 6months and some will try to push it to once a year😱
If your results were taken at the hospital clinic it can take several weeks for them to get back to your GP, if you GP took them then it's about a week and it should have been entered onto your medical records..
I would make an appointment with your sugery DSN so that you can discuss them, in the future I would ask if you can have your bloods done before seeing the DSN so that you can disguss the results at the appointment..
You can also request a print out of this information as well, you may find that your surgery might ask for a small charge for this very much depends how tight fisted they are really... But they can't refuse