My girl was performing oral sex on me and I finished in her mouth, completely. I specifically know that she tried to take everything. I am quite sure she didn't let any of the semen reach her hand... but, she had some saliva there when she was done...
After spitting out into the sink and washing her mouth (she may have just gotten her hands wet during this), she sat down to wash and used the same hand to just gently clean away her wetness on her vulva and vaginal opening (she used a lot of water from a toilet hose).. It wasn't was not more than 3-5 seconds.

I might sound paranoid, but... is there any chance of her getting pregnant?

Yes there is... How great is it? Not much.. but tell that to the 1 person of a million that contracts some unrepeatable fatal disease. Whatever the odds are... there is someone who is going to be that person.