Im 38+4 and i keep getting some sharp pains around my rib cage. I've timed them thinking they're contractions (ftm) and they'll come every 5 minutes but only last around 10-15 seconds, and for about an hour and go away and come back after a while. I know it's not gas or having to go #2 cause I'll go and sit on the toilet for a good while and nothing happens.

What can this be?