I Had Unprotected Sex With A Man Who Is 'fixed'

I had unprotected sex with a man who is 'fixed' about a week ago we used the pull out method as well.. He had his vasectomy done a little over 10 yrs ago. But its my second time ever having sex. I wa scared of pregnancy the first time but this time its worst. I keep having PMS symptoms but no period yet. My cycle was suppose to start around this time and hasn't yet. I'm irregular anyway but still very concerned.