I'm 30 weeks pregnant and just recently started having cramp like pains, is this bad?

Maybe. Women who are pregnant should contact the person designated by their obstetrician or midwife if they have cramps or contractions, bleeding from the vagina, or fluid leaking from the vagina...So you should follow up with your health care provider as soon as possible.
It could be. This could be nothing, but it could also be a sign that something is wrong. Call your ob/gyn as soon as possible or go to the er.