I was having intercourse with my wife, I pulled out then went to re-enter her when I heard a very loud snap and I felt extreme pain all the up to the head of my penis!
I now have a swollen like knob or knot at the base of my penis!
It now is ever so slightly differently shaped. What my have happened? Will it heal on its own?
Should I see my regular family doctor?

I have never heard of such a thing I would have been in the Er ASAP! Well if I were a man.

The pain in the head could be that you tore the small piece of skin between the head and the top of the shaft. I get that too, and it hurts, but it does heal. If that's the case, keep it clean and put some neosporin on it.

As for the lump, I don't want to give you a misdiagnosis, my best advice would be to see your family doctor.

There is a situation where the penis can break! Yes that's right. Get to a surgeon so that they can ascertain the action to rectify it. It will probably not heal on its own, the pipework (corpus cavernosa) has split-you probably need some surgery to fix it.