Always use a condom- Plan A. Double wrap if you think the guy has the capacity of a bull. Remember this... whoever you sleep with you are also sleeping with their historical partners and their historical partners as well. That could be, squared or to the exponent of 2 one hell of a lot of people.
Use a condom until you have reviewed your partners HIV test results. Smart but unromantic it could save your life enabling you to live long enough to kiss your grandchildren goodnight one day in the distant future. No condom- NO SEX- Finished!
Regarding the pregnancy question, use Plan B. Get it at your local pharmacy.
No condom, shame on you girl!