Embrace, I think that you are not really answering the question. Please ask your extra questions by using the mailing system in order to get your answers ;)
It sounds just like a classical exposion of the familiar to you.
So the best way to test your pet for the familiar characteristics is to open up your magickal space to him/her and see if there is any interest displayed by your furry friend. (Or shelled, or slimy... as the case may be.) If there is interest and even intervention in your magick, then your pet may be acting as your physical familiar. Same with being able to feel the enrgy.
That is a bond that can be worked on slowly and carefully, so he/she can find the best way to offer his/her help to you in your magick, and you can learn the best way to harness and respect what your friend has to offer. Remember, though, that a familiar usually finds us, when we least expect it. In your case, your familiar (possibly), found you while you were in your yard. It is hard to say when or where we might find our familiar, when we do, they deserve the utmost respect and kindness.
In some cases, your familiar will come to you without you even knowing it, or even casting a spell. This is because familiars are spiritual creatures that know to seek us out.
If you have an animal hanging around your home that just won't leave, this may be your familiar. Again, your case sounds just like it.
But remember that it is not too easy to guess when the animal you see is your familiar, you have to observe it for a while and during the time you will be able to tell if it is your familiar or not.
In case you feel more energy around you,as you described your situation, this might be a sign that it's your familiar, indeed.