I am 25 years old. I had my periods on October 9 to October 12. I had sex on October 13.. I have irregular periods. Still I don't get my periods. I did pregnancy test on November 16 and November 20. The result was negative. Is there any possibilities for my pregnancy?

Possible? Of course, you are having sex!! Could be your irregular period. What Birth Control are you using? PS, the pull out method isn't BC.

Often you would have gotten a positive result by this time if pregnant, but since you have irregular cycles, and can't use a missed period as easily for a possible sign of pregnancy, you may want to test again, or see what happens with your period this month first. If still any doubt, you can always ask your doctor about having a blood test done.