Have you had unprotected sex or a condom break? It's only a sign if you've engaged in activity that can get you pregnant. Some women do get bloating and cramping in early pregnancy but most don't have a lot of symptoms at all.
A light or missing period would be another sign. How about changes in appetite, peeing, breasts, emotions, smells, acne, gut function etc. Run a home pregnancy test when you are sure your period is late.