38 weeks and getting bum pains

Tash • Round 3 here I come. 👶🏼💛✨Due, Feb 2024 Already a Mama to 6yr old Jacob & 4yr old Evie. 💙💗
So I'm 38 weeks today and all day I've pretty much had pains/pressure pushing on my bum. It sounds so weird but that's the only way I can explain it. I'm also having period like pains that are coming sharp, fast and lasting only a few seconds. 
Could this be it?? Baby has been moving all day long, and I've been peeing like crazy. Every time I go to sit down the pressure I get is insane, it takes me ages to sit and get back up! 
I'm so nervous as it's my first. 
Anyone else felt like this before baby arrives? 💙