When is the time for real labour? Any difference between real time labour and a false alarm as this is third trimester, sometimes I feel pain when I walk and as if something going to come out ..

For my previous 2 pregnancies, I experienced bloody show then entered into read labor. For my 3rd pregnancy now, I am experiencing the same things as you have mentioned, cramps and uterus pressing. I find that whenever I am overtired during the daytime I will experience cramps and tummy hardening. However, after well rested it will go away. Another way to find out if you are in real labor is, time your contractions (tummy hardening that comes with cramps). You can download "contraction timer" apps to track the intervals. If the interval btween contractions is consistent, e.g. 15mins apart and the duration of pain is getting longer, this means you are in real labor.