20 weeks pregnant

I’m 20 weeks pregnant at 4 days today. & I’m having a baby girl 🥰

For about 2 weeks now I have the urge to have to pee often.

I feel movements very low in the abdomen, under the bellybutton, and that causes me to feel like I have to pee right away.

So i dont know if it’s air, gas, or the baby, or something else.

I have my anatomy ultrasound this coming Friday.

Can anyone help and guess whAt it could be?? I read online it could be signs of pre labor???