Given the symptoms, it is probable that you may have conceived, but the best way to say this would be by confirmation of the presence of significant serum beta-hCG
levels and a positive sonogram finding. It is possible that you may have gained some weight over the years on the depo shot and this could in turn make the requirement of the hormone higher. In essence, this could lead to decreased contraceptive
effect of the injection toward the third month. Please get further suggestions from your consultant. Take care.