It's considered irregular and you may want to see your doctor about it. Is there any chance you are pregnant?
It depends on why you didn't have it. Some women will deliberately run two months' worth of birth-control pills together without a break, in order not to have a period. It's not the greatest thing to do regularly, but it isn't "a bad thing." Some women skip a period for no discernible reason, then go on and have normal periods. That's not a "bad thing" either. Some women do skip a period and keep skipping them, because they are pregnant. Whether that is a bad thing or not, depends on the woman's situation and her interest in being pregnant. If you aren't pregnant and your period remains AWOL, see a doctor.