Week 13 begins the second trimester, and you are now roughly a third of the way through. A small bump may become visible as the womb grows upwards and outwards. For many women this is the week the constant bathroom trips stop.
Your body this week
As the womb moves up and out of the pelvis it stops pressing on the bladder, which is a relief that arrives without warning and is rarely mentioned in advance.
More blood is moving through the pelvic area. Some women find that increases their sex drive, and the NHS is clear that sex in pregnancy is safe unless a midwife or doctor has said otherwise for a specific reason.
Gums are the surprise of this trimester. Swollen, sore and bleeding gums are common in pregnancy, and the NHS advice is a soft toothbrush, gentle circular brushing, alcohol-free mouthwash, and rinsing with water rather than brushing straight after being sick — vomit is acidic and brushing spreads it across the enamel. In the UK, NHS dental care is free during pregnancy and for a year after the birth.
What you may notice
Swollen and bleeding gums, round ligament pains at the sides of the belly, headaches, nosebleeds, bloating, constipation, indigestion and heartburn, sore breasts, leg cramps, feeling hot, dizziness, swollen hands and feet, urine infections, vaginal infections, darker patches of skin, greasier skin and thicker hair.
Symptoms from the first trimester often persist for a few more weeks. Sickness does not stop on a schedule.
Burning when you pee, or needing to go urgently and often, is a reason to be seen — urine infections are more common in pregnancy and are treated rather than waited out.
Your baby this week
Around week 13, the figure quoted is about 7.4cm — peach-sized, in the NHS's comparison. It describes a population, and no individual pregnancy has to match it.
Movement is happening: at first jerky and random, later more deliberate. Most women do not feel anything until around week 17 or later. Some babies suck their thumb at this stage, which develops the sucking reflex needed for feeding after birth.
What care usually happens around now
If the dating scan and screening have not happened, this is usually the last stretch of the window — in England the scan is offered up to 14 weeks. Results from first-trimester screening often arrive around now.
The second-trimester screening test offered in the UK to women who missed the earlier window is usually available from around 14 weeks. Elsewhere the timetable and the tests differ, so ask what applies where you are booked.
This week's tip
Book a dental check-up this week. Pregnancy makes gum problems more likely, dental care is free on the NHS during pregnancy and for a year afterwards, and it is the one appointment that gets forgotten because it is not on the antenatal schedule. Say you are pregnant when you book.
When to see a doctor
Report any bleeding, severe pain, burning when you pee, a fever, or a headache with vision changes. Pregnancy warning signs covers the whole set, and it is worth reading once properly at the start of this trimester.
Seek care now: Contact your local emergency services or go to your nearest emergency department if you have heavy bleeding, severe or one-sided tummy pain, a severe headache with vision changes, sudden swelling of the face or hands, a fever, fluid leaking from the vagina, chest pain, trouble breathing, fainting, or a seizure. Femio cannot assess a pregnancy.
Frequently asked questions
My gums bleed when I brush. Should I stop brushing?
No — brush more gently, with a soft brush, and see a dentist. Stopping makes gum inflammation worse.
Why do I suddenly not need the toilet as often?
The womb has grown up and out of the pelvis, so it is no longer pressing on your bladder. Week 14 continues the easier stretch, and week 12 covers the scan behind you.