So I guess I'm in labor?

Felt nauseous and more consistently crampy today and my coworker touched my belly and said "you are having contractions!" So I called the Drs and they said I should go get checked at the hospital. I went home and rested a little and thought yeah maybe I really should get checked, I don't feel good. So I drove myself up, told hubby to stay home as it's likely nothing. They hooked me up to the monitors and they aren't picking up my contractions but when dr came in he did a cervical check and I'm 5cm dialated and 70% effaced and he is surprised I'm not in anymore pain than I am and didn't think I'd be as far along as I am. I am admitted and they said baby will likely be here tonight or tmrw. I'm sitting here now waiting for hubby to get here haha. This has all happened so fast. My fear was right tho, that I wouldn't know if what I was feeling was true labor or not cuz I've felt funny like this past 2 days and wasn't sure. It's 6/6/16 and my original due date is 6/11/16, first baby.