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You pull up your pants and they feel… a bit tight. That’s not so unusual, but if you’re sexually active and pregnancy is a possibility, you may be wondering whether you’ve just gained a little weight or if this is a sign you’re pregnant.

Want to find out whether last night’s burrito just caused a little bloating or you’re growing a whole new person inside you? Here’s what to know.

Obviously, to find out if you’re pregs for sure, you need to take a pregnancy test and confirm the results with your doctor.

A missed period is often the first sign that causes someone to reach for a pregnancy test. Still, many women don’t have regular periods to begin with. Factors like polycystic ovary syndrome, birth control, and certain health conditions may impact your menstrual cycle.

To complicate matters, implantation bleeding, which happens early in pregnancy, can sometimes be mistaken for a period.

It’s more common than you might think to miss symptoms of pregnancy (who can forget that TLC show “I Didn’t Know I Was Pregnant”?). Since everyone carries baby weight differently, people of all shapes and sizes are liable to miss the signs of a baby bump.

In fact, preliminary data suggests 1 in 475 pregnancies are “cryptic,” meaning the pregnant woman has zero clue she’s preggo until it’s time for birth. 😱

If your periods vary from month to month — or if you don’t have one at all — here are some telltale signs that could indicate your eggo is preggo.

Morning sickness is that infamous pregnancy symptom your mom warned you about (and the one she still secretly resents you for). Studies estimate that 70 to 80 percent of pregnant women experience nausea and vomiting, most commonly in the first trimester.

Despite the nickname, the urge to hurl doesn’t have to happen in the early hours. Nausea at any time of day might be a sign something’s up.

Pregnancy gives your body an extra dose of progesterone, which can cause your bowels to run a little slower than usual. It’s pretty common to experience constipation during pregnancy.

If you gotta pee seemingly every other second like an early 2000s Detrol commercial, your womb may be to blame. You may also feel an unquenchable thirst, no matter how many Gatorades or coconut waters you down.

That “can’t get off the couch” feeling might happen for all kinds of reasons — pregnancy among them. If you’re feeling extra tired or fatigued, pregnancy hormones might be at work.

Discovering that an inexplicable bout of spot bleeding has just ruined your fave pair of underwear = absolutely no one’s idea of a good time. It’s also a potential sign that you’re pregnant.

Light vaginal bleeding called implantation bleeding often happens 1 to 2 weeks after fertilization.

If you don’t usually get headaches and your noggin’s throbbing, it could be a sign of pregnancy. This could be from foods or other side effects, like lack of sleep and vomiting. Or it could be a tension headache from those lovely hormonal changes, higher blood volume, and extra weight.

A baby on board can put strain on your back. Some research suggests that about half of all pregnant women experience low back pain. While it’s most frequent during the second trimester, it can happen at any stage.

If merely standing up makes you feel like you just stepped off the Tilt-A-Whirl, you just might be pregnant. Pregnancy causes blood vessel dilation and a drop in blood pressure that can make your world a little blurrier than normal.

Feeling lightheaded or dizzy, especially when standing up quickly, is a common symptom during every trimester.

Maybe you normally crave things like pizza, triple-chocolate cake, or even a crisp green salad (are you a unicorn?). Now, inexplicably, you’re headed straight for a big ol’ cup of ice.

During pregnancy, the volume of blood in your body increases, which can cause anemia. It might sound like a strange craving, but folks with iron deficiency often get the urge to nom on ice.

No, you didn’t just imagine that. The skin around your nipples really can become darker — no suntan required. All kinds of changes to your nipples go down during pregnancy, even in the first few weeks after conception.

Some women may also experience nipple inversion or discharge from early milk production. If you have any bloody discharge, call your doctor ASAP. It could mean you have a tumor.

Sore, achy breasts are often a pregnancy hallmark, as hormones surge and your bod preps for milk production. Breast tenderness may show up as early as 1 to 2 weeks into your pregnancy.

The phrase “bun in the oven” actually makes a lot of sense, because you gotta crank up the internal heat to make a baby. An elevated basal body temperature (BBT) — the temp of your bod just before you hop out of bed — is a common symptom of early pregnancy.

Heads up, though: Stress, an infection, or a night of drinking can also cause this temp to rise.

Thought breakouts were a thing of your past, yet here you are with some annoying hormonal acne? It could be a sign your eggo is preggo.

Not all post-teenage acne is caused by pregnancy, of course, but skin changes often occur during the first and second trimesters.

Your body always works hard, but during pregnancy it works even harder. Your heart needs to send a lot more blood to your uterus, so it’ll start to work harder by week 5 (super early in pregnancy).

A higher heart rate and occasional heart palpitations can often signal pregnancy. But these changes could also be a sign of a serious health condition, so if your heart feels like it’s working overtime, chat with your doc to be sure.

Radiant skin can happen for all kinds of reasons — like the fact that you’re finally drinking enough H2O. But you can also get that “glow” from pregnancy-related hormonal changes.

Increased circulation and a surge in the hormones estrogen, progesterone, and human chorionic gonadotropin (hCG) can sometimes make the skin look extra luminous.

A little weight gain or a bit of bloat isn’t necessarily a baby bump in the making. Other possible causes:

If you’re concerned about the change and not sure what’s causing it, it’s a good idea to chat with your doctor.

Weight gain or bloating might mean you’re pregnant — or it might not. Still, for the sake of your health and well-being, talk to your doc about any unexpected changes you experience.

Play it safe by tracking pregnancy symptoms, taking an at-home test, and scheduling an appointment with your doctor or gyno.