It could just be round ligament pain, which varies in intensity. Putting some pressure on the painful area or waking slowly should reduce the pain. If it become prolonged and really intense then seek a drs help.
I had the same with my son. It's your uterus and/or abdominal muscles stretching. It's completely normal. With my first it was just the prickly feeling, now it's full on painful if I stand up to fast :)
Well from my experience they said it was the baby's hair. But you can ask the midwife or Dr. An when I had her she had hair on her head. But still call to make sure I could be wrong.