By 5 weeks of age, when the corners of your baby’s mouth curl up, you can safely attribute it to an actual social smile — unless, of course, you happen to detect that telltale odor that means it’s time for another diaper change.

And who better to practice those first smiles on than Mom and Dad?

So keep talking and singing to your baby — plus give your happy little cutie some smiles of your own — and that precious baby grin will keep your heart melting.

Something else your 5-week-old baby will smile about around now: music — whether it’s you singing your way through a feeding or the radio humming in the background.

Your baby’s acutely aware of other sounds too, like bells, barking dogs, running water and whistles. She may kick with pleasure at these sounds, cry out or quiet down to get a better listen (a lot depends on whether they’re sounds that became familiar in utero).

Just be sure to note which sounds calm down your baby best so you can recreate them when you need to most!

First things first: Stock up on staples. Fill your pantry and fridge with go-to basics like low-sodium chicken broth, whole grain bread and bread crumbs, olive oil, eggs, nuts and nut butters.

This way, your weekly grocery shopping trip will be easier to manage. Plus, knowing you’ve got key ingredients on hand before you start prepping a meal makes the process a whole lot easier.

Also, don’t be a slave to scheduling — let’s face it, as fun as Taco Tuesday sounds, things come up and you might decide at the last minute that you want nothing more than a bowl of cereal or PB and J. 

Save one slot a week for a leftover potluck and give yourself some extra wiggle room to switch things up so dinnertime stays low-pressure … and maybe even fun.

When an infant has a milk allergy, the baby’s immune system reacts negatively to the proteins in cow’s milk.

If the baby is breastfed, she’s reacting to the dairy her mother has eaten (the milk proteins pass through breast milk). If the baby is formula-fed, she’s reacting to the cow’s milk proteins in the formula.

In either case, the immune system sees the cow’s milk proteins as foreign substances, and in its efforts to fend off the invaders, the body releases histamine and other chemicals, which cause allergic symptoms in the body.

Symptoms of milk allergies in babies include: frequent spitting up, vomiting, signs of abdominal pain, diarrhea, blood in stool, lack of weight gain, hives, a scaly skin rash, coughing or wheezing, watery eyes and stuffy nose, trouble breathing or even anaphylaxis — a life-threatening allergic reaction and requires an immediate call to the doctor, 911 and/or a trip to the ER.

If your baby has symptoms of a milk allergy, see your pediatrician, who will likely perform a physical exam and an examination of your baby’s stool, discuss your family’s history of allergies, and maybe even perform a skin-prick test and refer you to an allergist for further testing.

If you thought you had until puberty set in to worry about blemishes tarnishing your sweetie’s skin, think again.

About 40 percent of babies develop infant acne, which commonly creeps up at 2 to 3 weeks of age and is usually gone before the 6-month mark.

Infant acne is caused by Mom’s hormones, which are still circulating in a baby’s bloodstream.

These pimples that pop up on your little one’s crystal-clear skin aren’t pretty, but the good news is they’re harmless and won’t leave permanent scars — just resist the impulse to squeeze them or apply creams.

The best solution is to keep the area clean (with water only) and let the pimples vanish on their own (which they will — and soon, too).

Even if you didn’t gain much excess weight during your pregnancy, and even if you shed most of your post-pregnancy pounds in the hospital, your post-baby bump will likely stick out for at least a few months or more after birth.

And that’s okay — after all, your skin is elastic, but it’s not spandex, and your uterus just stretched from the size of a pear to that of a watermelon. So it’s going to take a while to get back to stone-fruit size.

In fact, for the first few days after childbirth, you’re likely to feel abdominal cramping. That’s your uterus contracting as it starts to shrink. Plus, your abdominal muscles distended to make room for the baby.

Just remember, hold off on the crunches until you get the go-ahead from your doctor, especially if you’ve had a C-section.

Strawberry hemangiomas, also known as infantile hemangiomas, are soft, raised berry-like birth marks that often appear on your baby’s scalp, face, chest or back. They can grow quickly at first, but tend to stop by the time your little one is a few months old.

Strawberry hemangiomas are common in infants and usually fade away starting around baby’s first birthday, often disappearing completely between the ages of 4 and 5 years old, if not sooner. Sometimes scar tissue remains, however.

These birth marks form when a group of tiny, immature blood vessels cluster together. The best approach can be to see if the hemangioma will disappear on its own.

If not, talk to your pediatrician to find out which treatment option is best for your baby. If the hemangioma grows very large or is near or on baby’s eyes, nose or mouth (which can make seeing, breathing and eating difficult), the pediatrician will refer you to a specialist to discuss treatment options. 

For infants, the doctor will usually prescribe oral or topical medications and/or injections before considering surgery or laser treatments.

If you’re breastfeeding, you may have heard that nursing can serve as a form of birth control — and while that’s not entirely untrue, it’s not the whole story either.

Breastfeeding offers some protection — to a point. Exclusive breastfeeding, which consists of nursing at least every four hours during the daytime and at least every six hours at night, for the first six months postpartum and before the return of your period, is referred to as Lactational Amenorrhea (LAM). It is considered a form of birth control so long as all the criteria are met.

Breastfeeding outside of those criteria, however, especially when you’re supplementing with formula or solids and your period has yet to return, doesn’t offer the same contraceptive protection.

For this reason, your OB/GYN will likely suggest that you switch to another kind of birth control if you’re not actively trying to get pregnant (which your doctor should advise against until your baby is at least 12 to 18 months old).