Go to the doctor
yes that is totally normal, but not until later in your pregnancy.
she has two tattoos. One of a butterfly below her belly button and a wishbone right above her belly button.
This means you are piercing your navel .. navel is the phrase for the area above the actual belly button** ( **other wise known as the umbilical knot)
They are located on top of the kidneys and normally are slightly above the belly button (navel). But there is tremendous variation in where a normal belly button is located on the abdominal wall.
If you have pain below your belly button and just above your groin, you could be either pregnant (pregnancy discomfort) or growing some cancer (testicular cancer for men).
Standard ones go above your bellybutton and inverse ones go below.
If your talking about their belly button, that would be the "Happy Trail".
Abdomen
No, her belly button is not pierced. I've attached a related link below to show that she does not have one.
right below your belly button.
It could be herniated. See link below.
It is what a person would call a "belly" and is right below the chest. The "belly button" (umbilicus) is in the middle of the abdomen.