It goes a little something like this. You catch a glimpse in the mirror and notice that your breasts are bulging out of the cups on a demi-cup bra that used to fit you perfectly. Or, you suddenly have to fasten your favorite longline bra on the loosest hook. Maybe you can simply tell by looking at them. Regardless, your breasts are definitely bigger — and you can’t figure out why.

There are a number of reasons why your breasts may have grown in size — and luckily, they’re not typically any cause for concern.

In this guide, we’ll cover all the possibilities so you can get down to the root cause:

1.  Your period

About 14 days into your cycle your body goes through ovulation — which can cause a whole slew of symptoms that vary from woman to woman. One of them, as it turns out, is fuller breasts. According to research conducted by Johns Hopkins University, your boobs not only feel more sensitive and look perkier during ovulation but also even appear plumper. This is due to the fact that levels of the hormones estrogen and progesterone rise, causing an increased in blood flow to the breasts. So if you notice that your bra feels a little snugger or your cleavage is a little more dramatic for a few days halfway through your cycle, there’s a chance it’s due to ovulation — and rest assured that it will return to normal fullness after a few days.

2.  Weight gain

It makes sense if you think about it: if your body has gained weight overall, your breasts will as well. Some of this depends on breast composition: women who have more fat in their breast tissue may notice a bigger shift in size when they gain weight than those who have denser breasts with more tissue. Keep in mind that gaining a few pounds probably won’t have a big impact on your breast size. It typically takes a more significant gain to really notice a difference.

3.  Pregnancy

Speaking of weight gain, many women experience an increase in breast size during pregnancy. This is because the body is preparing for breastfeeding. As a result, the ducts in the breasts that are responsible for producing the milk will expand, leading to a fuller bust (as well as some tenderness as well). Some women even notice that their nipples and areolas get bigger! By the way, your breasts can also swell while milk is being produced during breastfeeding — but they’ll usually go back to their normal size a few months or so after you stop nursing.

4.  Birth control

Some medications may cause your breasts to inflate a bit, so this is another factor worth considering if you’ve noticed your size increase since starting any new prescriptions. For example, birth control pills are notorious for sometimes causing breasts to expand — this is because they cause levels of estrogen and progesterone to rise. It’s worth noting, however, that breasts will typically return to their normal size after a few months, so you’re most likely to experience this growth when you first start taking the pill. Within a few months of taking the pill, the breasts generally return to their regular size. This usually also happens if a person stops taking the pill.

5.  Chest exercises

Have you been doing some extra pushups or chest presses at the gym? These pectoral exercises won’t necessarily make your boobs themselves bigger, but as they strengthen the muscles beneath them, they can make them protrude a bit more from your torso.

If your breasts are looking bigger these days, don’t stress — there are a range of totally valid reasons why it’s happening, and for the most part, they’re nothing to stress about. There are plenty of perks to having big boobs! Still, if it’s worrying you, it may help to get the bottom of what caused this change. Depending on the cause, your breast size change may even be temporary. Once you’ve figured out why your breasts may have grown, you’ll want to get fitted by a professional. It’s crucial to wear the correct bra size to ensure you’re getting proper support, and if your bust line is expanded, there’s a good chance you’ve outgrown some of your bras.

We Highly Recommend

Whether you’re shopping for new everyday bras or lingerie for a special occasion, it’s always a good idea to seek out a second opinion. We know how hard it is to find bras that fit well and feel good, especially when you’re doing it on your own. If you’ve ever felt unsure about your bra size or you just don’t know where to go to find good bras, it’s time to let a bra fitter help.

Many specialty lingerie boutiques offer bra fittings. Their expert bra fitters will take the pain and frustration out of bra shopping and do all the work for you. Even better, their product knowledge can save you time and money. Plus, they know where all of the best bras are hiding.

If you’ve struggled with finding bras in the right size, it’s time to make a change. Visit our specialty store locator to find a store near you and schedule an appointment.

Happy bra shopping!

Featured image lingerie:

Charlotte Padded Bra 6901 in Purple Wine, Icy Blue, Red/Black