Is a pulling sensation from your you-hoo up to your belly on normal?

I was lying down and I sat up to grab my laptop and this strange tugging sensation just came out of no-where, and yes, it hurt. It felt like there was a string from my uterus attached to my belly on that was bing pulled. It lasted for about 20 seconds every time I used my stomach muscles. Not so bad to where I felt like I needed a doctor. I'm about 7 weeks preggo, and I just wanted to know if other women feel this. Is it normal???