Does anyone know what this could be?

So I’m just over 18 weeks pregnant -

So far been keeping well, and I’m really enjoying pregnancy !

So I’ve woken up this morning and before even getting out of bed I felt achey and stiff - especially around the lower back and the love handle area!

So I chalked it up to sleeping awkwardly or general stiffness etc.

Went to the toilet and sorry if this is too much info! (Was trying to pass a stool) and noticed the ache was worse with straining.. eventually managed though! But the Ache is still there..

I have put on a few pounds and belly is a lot bigger and rounder recently so not sure if it’s just general ligament pain due to the expanding belly!?

But the pain doesn’t hurt really bad it’s just more of a lingering ache which hasn’t eased up yet.

Also wondering if it could be from yesterday at work as I did walk quite a lot and am wondering if it’s all the walking that’s caused the ache ?

Or wind maybe ?

Had urine tested the other day and all was clear so don’t think it’s a UTI or anything..

Just wondering if it’s normal and other people have experienced this? :) thanks ladies !