Odd feeling in my lower tummy/bladder area. what is it!?

Lois
So im 14 weeks and over the past couple of days I've been getting a odd sensation which feels like it could be near my bladder area/lower tummy. It almost feels like a throbbing sensation/butterflies almost. 
It's not painful, it's almost a cringey feeling lol. It's so hard to explain. I'm not worried just curious what it could be. Could it be the baby? 😌 
This is my first baby and I'm quite overweight! Xx