Undercooked omelet?

I ate a really good omelet today and it was kinda burnt on the bottom; it tasted really good and cooked but the inside was kinda coated in creamy stuff that i assumed was the american cheese but i think it could have been a bit undercooked on the inside. Then i heated it up in the microwave later and a bunch of runny liquid came out of it but i ate it all anyway because I was hungry. Does this seem like it was undercooked? I am worried ill get salmonella