dont bank on that, my mum was severely ill for 3 days and 3 doctors didnt diagnose anything more than upset stomach/bug, when she went into hospital she was diagnosed after about an hour and taken to surgery instantly, her appendix burst and went gangrene, doctors rekon anothe 6-12 hours more and i wouldnt have a mum any longer but she was in severe pain for the days before surgery and couldnt eat/drink/sleep/move but it affects everyone differently. i reckon your uni should have an on call doctor for emergencies, just ring up the receptiony type place if youve got one and find out alternativley try nhs direct on the blower, theyre usually quite good