Don't quote me, but my understanding is that they take a 'wait and see' approach to early suspected ectopic pregnancies because in some cases in the early stages they can resolve themselves and at this stage they would be highly unlikely to see anything in your tubes or elsewhere, probably just a reaction in your lining. I think statistically most ectopics rupture between 7-12? weeks so whilst it's bloody awful to have to wait they take a more conservative approach and see what your hcg is doing etc before taking any more invasive action.