The selection of addresses, such as the house number, in a mapping application is not an exact science. This information is dependent on GIS data, how it is entered, and how the people entering it have decided on determining the way the block is divided. I've worked with this information with Enhanced 9-1-1 systems. Your house number, at least in the US, is determined by the post office. When GIS divides a block, for example, such as the 2400 block of a particular street, it starts with 2400, and ends at 2499, which most of us know is not the correct numbering system. If that is how it is entered in the GIS, then depending on where you fall in the numbering system, your location on the map could be quite different.
I know that doesn't help you with your location, but if emergency vehicles were using your address, they would be close and would verify via the displayed house numbers. If you were calling on a system that can process Phase 2 wireless calls, then you location is based on your handset, and they would find you there.