I noticed hair in places where they shouldn't be....why?

After having my first Boy I noticed a little bit of facial hair and around my areola area on both breast. Then after having my third child I noticed more hair than before and thicker. I've waxed the areas but I noticed that it was burning my skin, so I started threading it. Why is all this long thick hair growing all over me on my face, breast, stomach & toes? what is going on with my body?