I myself am 9 weeks pregnant, and everything you're reporting sounds perfectly normal! Every pregnancy is different -- you really cannot compare what you experience with this one to what you've experienced in the past. It's a new adventure every time!
I told my husband my stomach has never before been hard from gas upon WAKING! I have bloating and nausea every day, and I tend to suffer from intermittently hard and loose stools. All of these symptoms are both normal and easily explained by our ever-increasing hormones. Since your doctor has assured you this is normal and since these are new symptoms, I would not attribute them to anything other than pregnancy (if you had digestive issues before, it might be something like a food sensitivity, but since they're new, they should be normal pregnancy things).
From what I understand, the gas may last the entire pregnancy (although it's less distressing later -- right now, it's worst because we also have nausea and fatigue and all these other symptoms. A little gas later -- when we feel good and energetic, isn't as bad), but the nausea almost always disappears by the end of the 1st trimester. Also, once you're able to stomach iron supplements (probably by the 2nd trimester), you may well find yourself having harder stools than normal, although all the fiber you eat will definitely help with that!
In the meantime, here are a few tricks: If the gas is bad, you can take Simethicone (Gas-X and some other brands, I believe). Eating several small meals frequently throughout the day helps IMMENSELY with the nausea. Even though I don't WANT to eat when I'm nauseated, I feel SO much better when I have a little food in my stomach. My doctor also recommended taking 10 mg of B6 twice a day and/or taking a Unisom tablet to help with the nausea -- I haven't done this yet, but I have heard they're very effective. Speak with your doctor before you take anything, of course, but mine said those are perfectly safe.
Ginger is also very effective in settling a stomach -- steep some ginger tea (use real ginger), find some real ginger candies or cookies (the kind they sell at healthfood stores or Trader Joe's). Some find peppermint to be helpful as well. Finally, if the supplements are difficult, many people take 2 flinstones vitamins a day, just make sure you get the ones with iron. Take one in the morning and one at night -- I know an OB who did this because she couldn't stomach regular prenatals during hte first trimester.
Good luck!