first baby. need insight

Kiley • Baby Girl due June 28th 2017. 💕 excited to be a first time mom!
Been having back pain the last couple days and light cramping with loose stools and nauseous. My baby is measuring two weeks ahead. I'm currently suppose to be 35+3 but she's a bit bigger. She's already dropped and now I'm having more back pain than normal and cramps but only on one side. Like it's wrapping around one side. I don't want to go to l+d for every little thing since she's my first I'm not sure what to expect. And I feel like it lasts so long I can't time it.