2 day late period, 5 pregancy test all negative, my bf only rub on the outside of the opening of my vargina he never put it in. Could I be pregant? Last period was 20 - 24 dec 12

Possibly. You could be. Retest your home pregnancy test in one week and/or see your gyn. Also, if you are trying to conceive, to optimize your chances, your partner will have to enter you during sex. If you aren't trying to conceive, you still potentially could by just having "outercourse.".
Math doesn't add up. If your last period was december 20th your period wouldn't be quite due yet unless you have very short cycles? It is possible to get pregnant without penetration if he ejaculated.