Reasons You Might Miss Your Period
One of the most common causes of a later period is, unfortunately, stress. That's because when you're stressed, your level of the hormone cortisol increases. And, says Dr. Dardik, "that can delay ovulation or suppress it altogether."
Of course, "that's sort of a double whammy," Dr. Dardik says, because you're already stressed and being worried about a missed period isn't exactly going to help that situation. So if you've been through some trying times or experienced heightened anxiety recently, give yourself a break and be patient.
2. Birth control pills
"It's hard to reassure somebody that not getting [a] period doesn’t mean they're pregnant when they’re on the pill," Dr. Dardik says. "That’s the most common phone call that I will get."
However, the truth is that hormonal birth control is the other major cause of period weirdness. Dr. Dardik explains that the dose of hormones we get with the pill is very low these days. That causes the endometrial lining to grow very thin, which is a good thing because it makes your period very light. But the pill can also make it too light, even to the point that there's really nothing to shed — and no period to have.
But that's not a huge health worry because, as we wrote previously, you really don't need a period anyway..
3. Emergency contraception
The morning after pill is "a big dose of [synthetic] progesterone," Dr. Dardik says. That hormone surge prevents ovulation and it "can delay your period for up to a week," she explains. But if your period is at least a week late, this is definitely a situation in which you're going to want to take a pregnancy test to calm your mind.