Sore breasts in early pregnancy, and when to buy a maternity bra

You rolled over in bed and it hurt. Or you took your bra off the minute you got in tonight and that was the best bit of the day. You're six or seven weeks, there's nothing to see yet, and your chest feels like it belongs to someone else.

That's one of the most common early signs there is. Here's why it happens, what actually helps, and when it's time to stop squeezing into your old bra and buy a maternity one.

• Sore breasts are on the NHS list of early signs: they may get larger and feel tender, the way they can before a period.
• The NHS week 18 guide says your breasts may have gone up a size, particularly in a first pregnancy. Around 3 to 5 days after the birth, when your milk comes in, they look bigger again.
• For breast pain the NHS suggests a properly fitted bra in the day and a soft bra to sleep in. If you need a painkiller, paracetamol is usually the best one in pregnancy, and ibuprofen is one to avoid unless a doctor or pharmacist says otherwise.

Why your breasts hurt in early pregnancy

The NHS signs and symptoms page describes it exactly how most people would: your breasts may become larger and feel tender, just as they might before your period. The difference is that the period never turns up and the soreness doesn't go away.

It starts early. The NHS week by week guide has sore breasts on the symptom list at week 4, the same week a missed period is often the first clue. Some people notice the bra before they've done a test.

Then they grow. By week 8 the NHS says you may have slightly swollen breasts, and by week 9 "your breasts will be bigger now". Still no bump. That's why the bra goes long before the jeans do.

When do sore breasts start, and when do they stop?

They can start around the time your period's due. Stopping is harder to pin down, because the NHS doesn't put a date on it.

Sore breasts sit on the symptom list on every NHS weekly guide through the first trimester and well into the second, and the week 34 guide still has advice for sore breasts. So I wouldn't wait for it to pass before you sort out what you're wearing. Here's what the NHS weekly guides say about your breasts along the way.

What helps sore breasts

Mostly, the bra. The NHS breast pain page says to wear a properly fitted bra during the day and a soft bra to sleep in, and it lists pregnancy as one of the causes.

A properly fitted bra at seven weeks is very often not the one you were wearing at five. If the underwire sits right on the tender bit, or the band leaves a line round your ribs by lunchtime, that's the bra telling you.

The soft bra at night sounds fussy until you turn over at 2am and remember why you went to bed in one.

Painkillers need a bit of care. That same breast pain page mentions ibuprofen and painkilling gels, but it's written for everyone, and the NHS ibuprofen page says to avoid ibuprofen in pregnancy unless a doctor or pharmacist advises it. If you're pregnant, the NHS says paracetamol is usually the best painkiller to use. Your pharmacist can tell you more.

And save your money on the supplements. The NHS says there's little evidence that vitamin E tablets or evening primrose oil help with breast pain.

When to buy your first maternity bra

When your own bra starts to hurt or stops fitting. That's the honest answer, and for a lot of people it lands somewhere in the first trimester, long before anything else needs changing.

The signs are usually obvious once you look for them:

• the band digs in or rides up at the back
• the cups spill over at the top, or the wire sits on the sore bit
• you take it off the minute you're through the door

One of our reviewers, Lynette, put it the way a lot of people feel by the second trimester: "At 4 months pregnant I was struggling with fitting in traditional bras and also having really sore boobs."

Buy for the body you've got this month, not the one you think you'll have at 30 weeks. A bra bought big to grow into is too big now and probably wrong later. A soft stretch bra with no wire copes with a fair amount of change on its own, which is the whole point of buying one.

You'll most likely buy again, though. The NHS says you may be up a size by 18 weeks, and its week 35 guide suggests getting measured for a feeding bra that allows a bit of growth, because your breasts get bigger again when your milk comes in. NHS Grampian goes further: don't buy your nursing bra too early, wait until the last month for your first one, then get re-measured 6 weeks after your baby arrives.

That fits with buying early, it's just a different job. At eight weeks you want something that doesn't hurt. In the last month you want a bra that fits for feeding.

Ours have the feeding clip from day one, so if your size holds, the bra you bought at 12 weeks carries on. Kelly wore the Sensory one late on: "They were excellent towards the end of my pregnancy when I measured in at a 38F-G and really held everything nicely without being restrictive." If you've gone up a lot by the end, you go up a size. No bra stretches forever.

Which bra to start with

For a first maternity bra I'd go soft before supportive. You want stretch, no wire, no hooks digging in at the back, and a fabric that's kind to skin that suddenly hates everything.

Check the size guide first. It runs from a 28 to a 42 band and A to G cups, matched to S, M, L and XL. If you're between two sizes, take the smaller. Of our reviewers who mention fit, more say it comes up generous than small, and Victoria, who was on the cusp, said: "I was on the cusp of M/L according to the size guide but I'm really glad I went for the M."

The Sensory is the same soft, clip down bra with a bold black and white print inside the cup. That's for later: babies pick out high contrast patterns far more easily in the first few months, so it gives them something to look at while they feed.

If you're a fuller bust and the soft bra doesn't lift enough, the Support+ is the firmer one, and our maternity underwear guide compares all four bras side by side, the sleep bra included. The rest of what to buy early, and what can wait, is in when to start wearing maternity clothes.

When sore breasts are worth a call to your GP

Sore, heavy, growing breasts in pregnancy are normal. A few things aren't, and the NHS breast pain page is clear about them.

See your GP if the pain isn't getting better or painkillers aren't helping. Ask for an urgent GP appointment or contact 111 if you have breast pain with a very high temperature or you feel hot, cold or shivery, or if:

• any part of your breast is red, hot or swollen
• there's a hard lump that doesn't move around
• you get nipple discharge that may be streaked with blood
• one or both breasts change shape, or the skin looks dimpled like orange peel
• there's a rash on or around your nipple, or your nipple has sunk in

Yellow stains in your bra are a different thing. The NHS week 14 guide says that's probably colostrum, your first milk, and to ask your doctor or midwife to have a look if you're worried about any changes. You can mention anything at all at your next midwife appointment; it's what they're there for.

Questions we get asked

When do sore breasts start in pregnancy?

Early. The NHS week by week guide lists sore breasts from week 4, around when your period would be due, and the NHS includes them in its early signs of pregnancy.

How long do sore breasts last in pregnancy?

There's no set end. The NHS keeps sore breasts on its weekly symptom lists well into the second trimester, and its week 34 guide still suggests a light bra at night and a more supportive one in the day if they're sore. A bra that fits now makes the weeks in between a lot easier.

When should I buy a maternity bra?

When your own bra starts to hurt or stops fitting, often in the first trimester. Buy the size you are now and check again around 18 weeks, when the NHS says you may be up a size. Get measured for a feeding bra in the last month.

How many maternity bras do I need?

Two to start, one on and one in the wash. Add a soft one for nights if your day bra feels like too much in bed.

What are the yellow stains in my bra?

Probably colostrum, the first milk. The NHS says some women start to make it weeks or even months before the birth. Breast pads help, and if anything about it worries you, ask your midwife.

Can I take paracetamol for sore breasts when I'm pregnant?

The NHS says paracetamol is usually the best painkiller to take if you're pregnant, and to avoid ibuprofen, gels included, unless a doctor or pharmacist advises it. If you're not sure, ask your pharmacist.

If your bra came off the second you got in tonight, that's your answer. Have a look at the size guide, then the maternity bras, and the first trimester to do list has everything else worth doing this month.