How long after you started early labor contractions did you go into full blown labor?

witchy 🌙
This morning I had what started out as period-like cramping that I could ignore. Now they're coming every 10-15 min, lasting 30-45 seconds and they're getting progressively more uncomfortable/painful. It feels like period cramps mixed with intense gas pains. The midwife said it sounds like early labor.  
Did you experience this as early labor & how long did it take to transition?