HIV Risk? Very Worried

I am a 28yr old male worried about this encounter with a woman...

" On Nov 20th 2011 I had an affair with a 23 yr old woman that I didn't know that well it was a big mistake and I stopped seeing her a few days after ... we had unprotected sex once and I felt so bad that I wasn't into it and I tried not to go too deep .. it was doggy style "don't know if this makes a difference " .. after I asked her if I had anything to worry about and she said " no I'm clean I have only been with five people " and she said she got the "hpv" shots .. but I'm worried about HIV.. almost 4 months after Nov 20, 2011 my wife and I both got the flu .. now I'm freaking out .. but idk if i should be worried because a lot of people I know have been sick with flu symptoms as of late .. those are the only symptoms i have had to date ..Should i be tested for HIV?

PS. my wife has just stopped her birth control and has been having thick white discharge with itching and we are not sure what that is .. its not a yeast infection.. we used the vagisil screening kit and it said it was not a yeast infection... my anxiety level has gone up and this its killing me.. could this be related? now im not sure if its from the birth control or me please help

Thanks feed back is greatly appreciated