Breast changes throughout your pregnancy
Have you noticed that your breasts grow bigger and get a little sore each month, at some point after ovulation and before your period is due? These changes represent your body's very first preparation for breastfeeding. Your first pregnancy breast changes will thus happen before your period is due, and regardless of whether you are pregnant or not. Your breasts are heavier because your milk ducts and alveolar buds grow during this time. If you actually conceive, your breasts will begin to get heavier and bigger pretty soon. Some women notice a tingling sensation as their blood volume increases due to pregnancy.
Many women have sore and even plain painful breasts during this time. A good bra that supports the breasts well and does not irritate the skin can alleviate some of these feelings. A few weeks after your missed period, you may start seeing color changes. Specifically your areolae, those areas of sensitive and darker skin around your nipples, may become darker (and bigger too!). Your nipples can start sticking out more in preparation for breastfeeding as well.
As your pregnancy continues, it is possible that you will see veins underneath the skin of your breasts, or below the nipples. Your veins are more visible during pregnancy, and this change will usually disappear after you give birth or after you stop breastfeeding. Some women also develop bumps on their nipples called Montgomery's tubercules. You may be scared by these many women search the net to find out if they have developed "extra nipples" but they are totally normal and will definitely go away.
In the later stages of the second trimester, or during the beginning of the third trimester, you will probably start noticing colostrum leaking from the breasts. This is the early, very nutritious breast milk your baby will benefit from so much right after birth. Leaking milk can be a very strange experience! It shows that your body is working properly, so it is a very good sign. Ideally, you'd get a mammogram before trying to conceive. No matter whether or not you did get one, it is still important to continue checking your breasts regularly.
Only, don't be freaked out if you do feel various lumps in your breasts those will usually be your milk ducts developing, and getting clogged up. These will give you some pain when you touch them and will be hard. Still report any lumps you are worried about to your doctor. Finally, you may get stretch marks on your breasts. You may have expecting these ugly fellows on your abdomen and buttocks, but all that breast growth is just as likely to provoke stretch marks. They will never go away, but they will fade (and fade from your memory as you get used to them)
How to increase your comfort
All those breast changes can be quite annoying. You'll want to do everything you can to stay comfortable during pregnancy. A good supportive sports bra will help you stay comfortable, but... do you really want to invest in that? Those mothers who are planning to breastfeed (hopefully you, because breastfeeding offers numerous benefits to both you and your baby!) may be better off buying nursing bras. Nursing bras are not absolutely necessary to breastfeed. I breastfed for a total of four years without ever having owned a nursing bra, but many mothers love them.
If you think you are going to using nursing bras, you may like to buy them during pregnancy and use them as maternity bras, and save some money. Keep in mind that it's possible you are going to want to breastfeed long beyond a couple of months. Now, what should you do about that milk leakage? During pregnancy, but especially after your baby is born, nursing pads are life savers! I personally prefer cloth nursing pads because they are durable and save money. Disposable pads are also available, but they are expensive and probably not environmentally friendly either (I think they contain the same kind of chemicals as disposable diapers).