1. A pregnancy is nine months.
Is a pregnancy nine months? Well, sort of, is the best answer we have. Each month really has four and a third weeks. So 40 weeks is a full pregnancy. Whether that's nine months or not depends on how you count your months. But it's 40 weeks.
2. Heartburn during pregnancy means the baby will have lots of hair.
It's a very commonly held belief that if you have a lot of heartburn, the baby is going to have a lot of hair. Unfortunately, the amount of the baby's hair has nothing to do with heartburn. It's based on the amount of progesterone that is produced by the placenta, which causes relaxation of muscles above the stomach and allows acid to reflux. It's not uncommon for babies to be born with absolutely no hair, even in women who have severe heartburn.
3. Food cravings during pregnancy predict the baby's food tastes.
Cravings while you're pregnant don't necessarily indicate what foods your baby is going to like or not like, unfortunately. That would make the early part of parenting easier for most women. There is some evidence that suggests that if you crave very specific things, you might be nutritionally deficient. So if you're having very odd cravings, you should speak to your doctor about it.
4. Pregnant women can't dye their hair.
Pregnant women can safely dye their hair, as long as it's done in a well-ventilated room, where the fumes aren't going to expose anyone to any problems. If you get it done in a salon, that's great — as long as they're moving air through well, there's no problem at all.
If you dye it at your house, just make sure you have the window open, or that the vent is working well. I would avoid any sort of blowout because they contain formaldehyde, and that's not safe for pregnant women.