They had to break mine the first time too. I'd gone 5days having contractions but because my waters hadn't broken they wouldn't have me in. I was well past my due date so by day 5 I went in & said I wasn't leaving 😂
Lower back pain was how it started both times with me so it could be. First time I was in pre-labour for 5days though so wasn't much I could do until my waters broke. 2nd time was quicker thankfully!
If anything go get checked hun I had to have gas&air before I was even dilated cause of how strong the pains were, but to me it does sound like labour xx