Pregnancy calendar - Week 13

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week 4
week 5
week 6
week 7
week 8
week 9
week 10
week 11
week 12
week 13
week 14
week 15
week 16
week 17
week 18
week 19
week 20
week 21
week 22
week 23
week 24
week 25
week 26
week 27
week 28
week 29
week 30
week 31
week 32
week 33
week 34
week 35
week 36
week 37
week 38
week 39
week 40

Your baby’s development

At 13 weeks pregnant your growing baby now measures around 8cm. They’re now very active, and stretching, kicking and turning, although they’re still far too small for you to feel it. The kidneys are starting to work and are now starting to send urine to the bladder. Each week, your baby’s proportions become much more like that of a newborn baby, and their head is now about a third of the size of their body.

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You & your body

During this stage of pregnancy, breasts can start to feel a bit lumpy – but don’t worry, it’s just that your mammary glands and ducts are developing in time for the birth. Your breasts may soon start making a thin yellow liquid called colostrum. This is packed with nutrients and will be the first milk that nourishes your baby after the birth before their regular milk starts to flow.

The good news is that size doesn’t matter so even if your breasts are small, you should still be able to breastfeed if you want to!

Did you know?

Some midwives recommend switching to non-underwired bras during pregnancy. Although it hasn’t been proven that underwires could be harmful, they can become uncomfortable or restrict the natural changes that your breasts go through, and interfere with your developing milk ducts. If fitted properly, underwired bras are fine in the first stages of pregnancy but near the end it’s best to switch to a non-underwired one. There are plenty of good options around that will give you all the support you need.