Is this labor?

I’m 40 weeks today. All week I’ve had contractions on/off nothing consistent and they’d eventually stop. This morning I woke up and I’ve had tightening so I just started to time them. They’re not painful. I’ve tried walking, cold water, changing positions. With my first baby my water broke so I’m unsure about if I should go in or not. I thought contractions were painful and intense. I’m also having intense heartburn which sucks