When your period hasn't been showing up when it's supposed to, it might be related to perimenopause. After all, that's its hallmark.
But it's also possible that it's because of something else, like an indication that menopause is still a long way off: pregnancy. Women can actually get pregnant during perimenopause, so if you're concerned about infrequent periods, take a pregnancy test. You're not officially in menopause until it's been a full 12 months since your last period. Until then, enjoy the savings on feminine care products (which never seem to go on sale).
Periods during perimenopause can also get shorter and lighter -- or longer and heavier, or a combination of the two. If you notice anything that simply doesn't feel right, like heavy clotting, trust your intuition and make an appointment to get yourself checked out.