cramping 17 weeks

Is cramping at 17/18 weeks pregnant normal? I have been having minor lower abdomen cramps for weeks but especially bad today. They feel like period pains. I am drinking water and laying down and I had some paracetamol (which I never take in pregnancy normally so you know it has to be bad!) which has helped but they're still there. This is my third pregnancy and I don't remember them being this bad the last two pregnancies. I have had round ligament pains in all pregnancies (the first pregnancy I ended up in hospital with them, needing strong pain killers) but I feel like they are different to this. Am I stressing over nothing?