Period, Pregnant or something else

[Scorpio8]

I could really use some advice on lower back pain I am experiencing.

I am due on and yes it's possible I could be pregnant but had very bad constipation. I had laparoscopy so not sure.

It feels like really bad period pain but bloated and lower back can barely walk but feel like I need to go loo. I am going to do test but want to wait until Sunday.

I just feel really bad stomach ache. I be shocked if I was pregnant this quick.

Any advice

Why wait until Sunday when you can answer the question today ?

Yes I probably should just rule pregnancy out first.
I have never felt like this with period. But it could be something else too.
I was waiting because it does still feel like my period is coming.