Normally you go through your pregnancy gaining weight then expect to lose it after your pregnancy ends. Some people take "eating for two" literally and eat twice as much, then gain more weight than they need or should. Some people are careful and make sure they gain exactly the weight they need to gain and some women even end up losing due to morning sickness or worse.

When you have the baby, there is a certain amount you do lose immediately; due to the baby's weight and amniotic fluid. You may get into a new postpartum workout routine or you may start dieting, you could also be one of the lucky ones who lose weight with breastfeeding.

If you're eating more or eating unhealthy, you can easily gain weight. There are some medical concerns since pregnancy can trigger medical problems.

NEXT: HERE IS SOME MAJOR ADVICE FOR GETTING PREGNANT AFTER AGE 35

Lifestyle changes can cause you to gain weight, sometimes without realizing. If you were very active before having your baby and you suddenly quit going to the gym or working out as much, that can cause you to keep weight or gain. The first few months are the most tiring due to baby's constant feeding schedule, that means a lot of late nights and not getting proper sleep can cause your body to pile on weight and crave unhealthy comfort foods like carbs.

Even if you try to remain active, there is the tendency all new moms (and moms) have of putting the needs of their kids first, that can also lead to neglecting herself.

Just because lifestyle and overeating tend to be the main reason, there are some reasons to be concerned. Postpartum hypothyroidism is a possible cause if you're taking care of yourself and still gaining. If it comes with fatigue and other symptoms of hypothyroid, it's best to see a doctor.

So how can you avoid the dreaded postpartum weight gain?

Don't start too soon, if you try to start working out too soon (before your doctor releases you, normally at 6 weeks), you can injure yourself and cause a longer waiting period.

Stick with slightly higher calories if you're breastfeeding, they recommend between 450 to 500 extra but no more is needed.

Remember, don't go in too soon to cut calories. When you're breastfeeding you need an extra 500 calories a day (give or take).

Breastfeeding does help with some weight loss as well.

Make sure your extra calories are healthy and not empty, reach for fruit instead of chocolate or a vegetable plate instead of the meat and cheese.

If anything rings an alarm or sets off a red flag, you do need to call your OB.