Sore boobs are a common early sign of pregnancy, but they can also signify that your period is imminent. If you think you may be pregnant, the best thing to do is pick up a home pregnancy test.

Sore boobs can occur for many different reasons. Some relate to hormones that ebb and flow, not just during pregnancy, but also during your regular cycle.

There are some distinguishing features that often make sore boobs a little different in pregnancy.

Like breasts themselves, breast pain comes in many varieties. It can happen in one or both breasts. You may feel it all over, in a specific spot, or moving outward into your armpits. The soreness can be constant, or it can come and go.

During the earliest weeks of pregnancy, breast pain tends to be dull and achy. Your boobs may feel heavy and swollen. They can be super sensitive to the touch, making exercise and sex play very uncomfortable.

For many people, the nipples are particularly sensitive in these early weeks. They can be so tender to the touch that it hurts to dry off after a shower or put on a bra. But extreme nipple sensitivity typically passes within a few weeks.

As the first trimester progresses, you may notice fullness and heaviness rather than tenderness. Some may also experience a tingling sensation in the nipples and areolas during the first trimester.

Sharp breast pain, which can feel like a knife being stabbed into a specific area of one breast, isn’t common during pregnancy. While it can happen, this type of pain is less common during pregnancy.

Breast pain is often the first symptom of pregnancy, occurring as early as one to two weeks after conception — technically, weeks three and four of pregnancy.

That sore boob sensation peaks in the first trimester because your body is flooding with hormones. These hormones prepare your body to grow the fetus.

Hormones work quickly to prepare your breasts for breastfeeding. Blood flow to the area increases and your boobs grow larger. This growth can also be painful, sometimes causing skin irritation and itching.

The milk ducts in your breasts also grow to prepare for breastfeeding. And hormones stimulate the growth of milk-producing glands.

Pain is not the only breast-related symptom you can expect during your pregnancy. During your first trimester, you may also notice blue veins pumping extra blood into your breasts and changes to the size or shape of your nipples.

During your second trimester (weeks 13–26), you may notice that your areolas — the pigmented areas around your nipples — have grown darker. And they’ll continue darkening throughout the second and third trimesters , too.

You may also notice tiny bumps on the areolas and wonder what is going on, but again, this is completely normal. These are called Montgomery’s tubercles. They’re oil-producing glands that lubricate the breasts during breastfeeding and make the process a little more comfortable for you and your little one!

During the second and third trimesters you may also begin leaking a yellowish fluid called colostrum.

Colostrum is an immune-boosting fluid that your baby will drink in the days following delivery, before your milk comes in.

Nipple discharge can happen anytime, but it’s particularly common during nipple stimulation. Nipple discharge can vary in color from creamy white to yellow, green, or brown.

Bloody nipple discharge can also happen during pregnancy. Usually, it is the result of growing milk ducts, but sometimes it can be a sign of a blocked duct. You should notify your healthcare professional if that happens, as it can be a sign of a more serious condition.

In the final weeks of your pregnancy, you may notice that your breasts have become even larger and heavier than before. Nipple discharge may become more frequent. And you may notice red streaks known as — you guessed it — stretch marks.

Breast pain is indeed one of the earliest signs of pregnancy. It can appear in as little as one to two weeks after conception.

Because it may appear before you notice a missed period, breast pain can sometimes be a useful indicator of pregnancy, but it’s by no means definitive.

If you’ve been trying to become pregnant and are experiencing unusual breast pain, you may want to go ahead and take a pregnancy test. Just remember, it may be too early for an accurate test result.

The symptoms of early pregnancy are very similar to the symptoms of your regular period. So how do you tell the difference?

Short answer: It’s not always possible. This is especially true if you’re someone who typically experiences breast pain during PMS.

Prior to hormone levels dropping before you get your period, your progesterone levels are elevated. Breast pain is a very common symptom of these changes. The best way to tell the difference is to see if your period comes or take a pregnancy test.

If you notice one or two days of light spotting, but no normal period, this could indicate implantation bleeding and pregnancy.

Sore boobs during pregnancy — or before or during your period, for that matter — is very common and generally nothing to worry about. Your breast pain might also go away after the first trimester, which is also normal and will come as a relief. Like morning sickness, some symptoms do go away once you’re farther along.

If you are experiencing breast pain and you don’t get a period when expected, speak to an OB-GYN to rule out pregnancy.

If you are pregnant, chat with your doctor about your breast pain and what to expect as your pregnancy progresses. Typically, it goes away before the second trimester.

Remember, bring any suspicious lumps to the attention of your doctor as soon as you can.