# Pregnancy Week by Week: Your Guide from 4 to 41 Weeks | Clever Mum

> Pregnancy week by week — what your baby looks like, how big they are, what you might feel and what to focus on, from 4 to 41 weeks. NHS-aligned, answer-first.

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Week by week

 
# 
Pregnancy week by week

 
Pregnancy week by week — what your baby looks like, how big they are, what you might feel and what to focus on, from 4 to 41 weeks. NHS-aligned, answer-first.

    
 
Quick answer — How is pregnancy counted in weeks? 

 

Pregnancy is counted from the first day of your last period, not conception — so you're
        already about 4 weeks along when you miss a period. A full-term pregnancy is around 40
        weeks, split into three trimesters: weeks 4–12, 13–26 and 27 to birth. Use our due date
        calculator to find your exact week.

    [Work out your week →](/tools/due-date-calculator/)    
## First trimester

 Weeks 4–12   [   4 weeks
 Size of a poppy seed  → ](/pregnancy/week/4/)[   5 weeks
 Size of a sesame seed  → ](/pregnancy/week/5/)[   6 weeks
 Size of a baked bean  → ](/pregnancy/week/6/)[   7 weeks
 Size of a blueberry  → ](/pregnancy/week/7/)[   8 weeks
 Size of a raspberry  → ](/pregnancy/week/8/)[   9 weeks
 Size of a cherry  → ](/pregnancy/week/9/)[   10 weeks
 Size of a strawberry  → ](/pregnancy/week/10/)[   11 weeks
 Size of a lime  → ](/pregnancy/week/11/)[   12 weeks
 Size of a plum  → ](/pregnancy/week/12/)    
## Second trimester

 Weeks 13–26   [   13 weeks
 Size of a lemon  → ](/pregnancy/week/13/)[   14 weeks
 Size of a peach  → ](/pregnancy/week/14/)[   15 weeks
 Size of an orange  → ](/pregnancy/week/15/)[   16 weeks
 Size of an avocado  → ](/pregnancy/week/16/)[   17 weeks
 Size of a turnip  → ](/pregnancy/week/17/)[   18 weeks
 Size of a sweet potato  → ](/pregnancy/week/18/)[   19 weeks
 Size of a mango  → ](/pregnancy/week/19/)[   20 weeks
 Size of a banana  → ](/pregnancy/week/20/)[   21 weeks
 Size of a carrot  → ](/pregnancy/week/21/)[   22 weeks
 Size of a papaya  → ](/pregnancy/week/22/)[   23 weeks
 Size of a grapefruit  → ](/pregnancy/week/23/)[   24 weeks
 Size of an ear of corn  → ](/pregnancy/week/24/)[   25 weeks
 Size of a swede  → ](/pregnancy/week/25/)[   26 weeks
 Size of a red cabbage  → ](/pregnancy/week/26/)    
## Third trimester

 Weeks 27–41   [   27 weeks
 Size of a cauliflower  → ](/pregnancy/week/27/)[   28 weeks
 Size of an aubergine  → ](/pregnancy/week/28/)[   29 weeks
 Size of a butternut squash  → ](/pregnancy/week/29/)[   30 weeks
 Size of a cabbage  → ](/pregnancy/week/30/)[   31 weeks
 Size of a coconut  → ](/pregnancy/week/31/)[   32 weeks
 Size of a large jicama  → ](/pregnancy/week/32/)[   33 weeks
 Size of a pineapple  → ](/pregnancy/week/33/)[   34 weeks
 Size of a cantaloupe melon  → ](/pregnancy/week/34/)[   35 weeks
 Size of a honeydew melon  → ](/pregnancy/week/35/)[   36 weeks
 Size of a romaine lettuce  → ](/pregnancy/week/36/)[   37 weeks
 Size of a stick of chard  → ](/pregnancy/week/37/)[   38 weeks
 Size of a leek  → ](/pregnancy/week/38/)[   39 weeks
 Size of a mini watermelon  → ](/pregnancy/week/39/)[   40 weeks
 Size of a small pumpkin  → ](/pregnancy/week/40/)[   41 weeks
 Size of a watermelon  → ](/pregnancy/week/41/)[   42 weeks
 Size of a watermelon  → ](/pregnancy/week/42/)   

Size comparisons are approximate and just for fun; every baby grows at its own pace. This is
      general information, not medical advice — your midwife and the
[NHS week-by-week guide](https://www.nhs.uk/pregnancy/week-by-week/)
are your sources for personal antenatal care.