FTM and I feel like a noob

beautifullife322

For the past week I have had this terrible back ache. Then the last two nights or so it comes with menstrual like cramping that is consistent across my tummy with the occasional tight cramp that last like 30 seconds or so. At my 36 week appt. on 12/28 I told my doctor about this and that I was up all night vomiting with diarrhea and he sent me to L&D to have fluid IV, a non stress test and ultrasound done I am also dilated 1.5cm. I am afraid that if I am feeling awful, crampy, lots of pelvis pain, back ache and tight cramps all the time how will I know when I am in labor? Nothing I read tells me what I am looking for as far as contractions go and everything I have read them to be is just what I am experiencing. But at L&D they said there were none on the monitors.