I think you will probably know, but depending on your pattern of labour, you might not know until fairly late on. Like you, I was induced with my first, I felt plenty of BH beforehand and really thought I was going into labour the few days before I got induced, I suppose in some ways I was as there were some cervical changes and my water broke, things just stopped happening once my water broke!
I tend to have a lot of BH, so it's hard to tell what is early labour and what is just lots of them. If I was having early labour contractions I didn't notice them and I went into labour in the bath and it really was obvious it was labour, within minutes I was vomitting and shaking and into full blown transition. I was so glad that that happened in the hospital I was going to birth at, so I only had to transfer upstairs to get to labour and delivery!
Anne, Christian mummy to Nathanael 05/28/03, Ada 06/10/05, Grace 05/24/09