I think i have a stomach ulcer? HELP?

i am really scared i think i have stomach ulcer. there is a gnawing pain on the left side of my belly on after i eat. but this is only when i eat bigger meals (like lunch / dinner) not snacks. it started yesterday (wed) before i ate lunch and i was really hungry but i thought it was just gastric. then after lunch there was still pain but it faded away, and since then after meals i would get this pain. i thought it was nothing until i searched the web. do you think i am ok? what should i do? but all the websites say the pain is in the upper stomach but i don't know where is that. please help! is it ok if i put it off for one month and see what happens or should i go to a doctor straightaway?