The answer was ectopic pregnancy, the patient was left at home (because the crew believed she had gastroenteritis after eating uncooked chicken) and was dead the next morning from subsequent rupture and exsanguination.
Red flags for were her race (non-White), age (> 35), IUD, smoker and vaginal bleeding, all of which are higher risk factors for ectopic pregnancy so putting all that together with her vague symptoms warranted immediate referral to a Doctor.
I can also see how this one would be very easy to miss; the risk factors are subtle and unless you actually know them then they can easily be overlooked or explained away, as can her vaginal bleeding and abdominal pain either to normal mensturation (as she did not feel different than normal) or abdo pains to her confounding symptoms of an upset tummy; especially given that the pain was not severe nor typical of say, appendicitis (no RIF pain) or an infection (no fever)
But, in saying all this, it is simply not possible nor sensible to simply transport everybody so we will continue to see each year a very small number of patients who are inappropriately not immediately referred to a Doctor (I think at last count over the last 2 years we might have had 5 or so)
Hope you learnt something anyway