When to go to hospital?

Deanna • Got my BFP 11•15•2015 Due 07•25•2016 🌻
I'm currently 40 + 3. I had only dilated 1cm at my last appt on Tuesday even after my doc trying at the previous 3 appt to try & get my cervix to dilate. Had a membrane sweep this Tuesday as well and have been losing pieces of my plug since. Since Tuesday night I've been feeling a lot more pressure as well as my back hurts, hips are sore and I'm feeling a little crampy. I have the occasional burning sensation when my stomach contracts but they are super irregular. My question is , I'm a FTM & I know everyone feels labor and other pains differently and I'm not sure what to do. Was debating calling my doc to ask to be checked this morning or am I just wasting my time because I'm not having true contractions or anything? I have an appt tomorrow morning but I've felt like this for almost 2 days now & im so ready for this baby to come. I don't know if what im feeling really means anything :(