Braxton Hicks contractions are irregular, some can get quite uncomfortable, but the real and regular contractions are even more painful. Braxton Hicks can be like a period cramp, while real contractions are maybe 10x stronger, and the intervals are closer.
So yes, time the pain.. pack your hospital bag.. look out for the other signs of labour like show and leaking liquor (ambiotic fluid). If your contractions are extremely painful and about 1 in 5-10 minutes, especially if you have the other signs, then you’re likely in labour.