Real contractions feel different for ppl, but most commonly they feel like period cramps. If you happen to start feeling slight cramping that comes and goes, just pull out a timer and time them. If they get worse and the time between them is regular they are probably real contractions.
time the pains, if they come in intervals, like every 3 minutes or every 15 minutes or so, then theya re contractions, but if they don't come in intervals for example you get pain, then two minutes later another pain, then 5 minutes later another one, then 1 minute later another one, then 9 minutes later another one, then these are Braxton hicks,.... I hope I helped
When you have real contractions, you'll know it. Real contractions come at regular intervals and become increasingly more intense. Braxton hicks go away and are irregular in timing.