Most likely nothing is wrong. Some women have infrequent periods their whole lives while others have stretches of time with periods that come every few months. Most of the time, having long stretches between your periods is due to lots of exercise, weight loss, physical or emotional stress, or occasionally chronic illness. If you are healthy and at an appropriate weight, not exercising a ton, and not under any more stress than usual, this is just who you are. The good news is that your bones will still be strong and you will still be just as able to get pregnant later in life even if your period only comes every 3 months or so. If you start having even longer stretches between your periods (more than 3-4 months) or if you are feeling stressed or losing weight, you really should see your health care provider and talk about it. Sometimes infrequent periods are a bonus and sometimes they’re a pain. If you are frustrated by the lack of predictability, you can use medications to regulate your cycle. Talk to your health care provider about all of your concerns.