Should I call off work?

If you don't feel well enough to go to work then call (whoever)as soon as you can before your shift and tell them that you wont be in today.
Your health comes first. You have to take care of yourself or you may not be able to work any day.

In physical pain, sounds like an excellent reason. You have other income streams.

don't go, standing for 5 hours with cramps will be hell

Call them tell them you can't function because you're sick

Call out sick. You are not up to it today

You know you want to do, do it!

If its sunny, pull a Sickie!

Yes

It depends. Is it important to you to keep the job?

What do you get paid an hour?