ISPs usually allocate IP addresses 'dynamically'. That means that they've got a bank of IP addresses allocated to them and, whenever you connect to the internet, one is randomly allocated to you. If you disconnect, that IP address becomes free and it will be allocated to someone else. (When you connect to the internet again you'll be given a different IP address).
It's possible to have a 'static' IP address (i.e. one that never changes) but you normally have to pay extra for the service. (Generally you don't need a static address unless you're hosting a web site on your own computer, rather than on a host's server).
If you Google your business, and your IP address is shown, it's likely that the address shown is simply one of the many which might have been allocated to your account over a period of time. Other internet users, with the same ISP, might well have the same IP address listed.
One of the problems with dynamic IP addresses occurs if someone has sent out lots of spam from an address which is later allocated to you. Spam-blocking services might then filter out any mail from that IP address, meaning that your own emails don't reach heir intended recipients.
To see your current IP address, simply click here:
http://whatismyipaddress.com/
Chris