Stomach pain during pregnancy

Dearest one and all. Here, I wanna ask a question again. Today am 13W 4Ds pregnant. It's been more then 3 weeks that I have stomach pain everyday. Not severe pain but mild one. Mostly in the morning and evening. Is there anyone having the same problem? I can't go to doctor untill 20 weeks. The pain is around the navel area. Could gas pain last this long? So if anyone knew anything about this, I would be very glad.