39 weeks with severe contractions + cramps

So today I had a coffee but it was decaf and it triggered contractions which were all over the place from 4 minutes apart and 30 seconds long to 2 minutes apart and 1 min+ long. Walked around and they weren't so bad. Laid in bed and now I have such bad cramps. I have an appointment tomorrow morning. Should I wait? I think they're bearable but at times I want to cry. Here's a picture of the contractions at their worst