HIV probably won't show up well until 3 months, but 2 weeks should be enough time for most other things to show up. You can always call a clinic that deals with sexual health a lot and ask them when would be a good time to get tested. Certainly go in if you start getting a fever, spots, discharge, etc. Fortunately for you, guys are slightly less likely than girls to catch an STD from a single encounter, since they don't have so much mucous membrane surface for transmission.
If it's been less than 5 days since this happened, she can still take the morning after pill. It is ok to ask her, since you could be on the hook for child support if she ended up having and keeping a baby you helped make. It's also ok to ask her when she was last tested for STDs and if she was clean then, and how many partners she's had since then, especially if the sex was unprotected. She might get offended if you ask, but you have every right to since your health is in question.
A good thing for you to know is that if you're under 26, you can now get the Guardasil (HPV) vaccine. There's no solid evidence yet that it will protect you from HPV related anal or penile cancers, but it absolutely can help prevent it from spreading (and genital warts are a pain to have, and a risk to any partners you have).
Sorry to ask but, Every 8 months I check what?