When is cramping not normal

So Friday in the night I got up to pee and could barely walk the pressure was so bad the pressure eased the next day but I had period like cramps ,I’ve had them everyday now and each day they get worse along with the pressure on and off I’m thinking maybe baby grew a bit and my body’s expanding but when is cramping something to worry about ? I’ve been reading it’s normal and can be down too dehydration or could be preterm labour this is my second baby and I’m 30 weeks 3 days