at what stage do you take stomach pains seriously?

[WhereDoIGoWithThis]

Was taken to hospital in September with severe stomach pains with suspected appendicitus had a laparoscopy but did not take appendix out as it wasn't inflamed.
Since about 7 this morning had bad stomach pains getting worse over the past hour or so. When do I start to take it more seriously and get it looked at?

As it's been going on all day and is continuing to get worse I would get yourself seen tonight

Ring the out of hours GP - you are likely to need to see a doctor tonight. (I'm a GP)

With your history I'd call your duty Gp immediately.