Yes and Yes. If you are a man and do not have any visible warts, you will not know if you have it or not since oyu cannot be tested for it. The rule of thumb is if you've had 4 or more partners in your entire life, then there is a good chance (80%) that you have it. Basically, its 20% per partner but all it takes is just bad one. Oral sex is not safe and never was safe. Condoms provide 50% protection. About half of the people who have HPV, have no symptoms (no warts). Read up on this virus and understand the risks.
http://www.cdc.gov/std/hpv/stdfact-hpv.htm