pain in my belly

Vianey
I have been having some pain on my stomach like in the front . It started in the morning (3am ) also felt my belly getting a little bit tight i was so uncomfortable. Now If am sitting down and get up i get a small cramping feeling but it goes away then i walk and it comes back again it feelings like cramp and a sharp pain. I really dont know what it is or why its happening. Could it be signs of labor ? I am a FTM and 39 weeks today .