Usually, it would not be considered 'unprotected sex' from a birth control standpoint if you were taking your pill consistently. However, since you're having trouble doing that you do put yourself at higher risk.
Since you haven't been on the pill very long, some of the changes you're feeling may be due to that. You can ask your doctor or pharmacist, or check the informational insert that comes with your pills for side effects.
You are correct that you are unprotected from an STD standpoint if your boyfriend isn't using a condom.
You can take a Home Pregnancy Test if you'd like. You can also see your doctor to find out what is causing your symptoms. If you're concerned that a daily pill might not be a good birth control option for you, then you can also speak to your doctor about that.
Please call your doctor back and ask what the tests mean and why you're having an internal ultrasound on the 11th. You need to understand what's going on and communicating with your doctor is an important place to start.
Many members have posted that they, or someone they know, has become pregnant using the "pull and pray," "withdrawal" or "pull out" method. According to this chart on Birth Control Failure Rates , 27 women out of 100 will be pregnant at the end of the year if they use this method.
You can go to a pregnancy clinic and get a blood pregnancy test done if you don't want to see your doctor. I would encourage you to see your doctor however. He or she can help explain the abdominal movement, nausea and other symptoms, and can address whether or not the weight loss may have impacted your period.
Bleeding is not a sign of a normal pregnancy, but it can happen with an Ectopic Pregnancy , along with pain. As for Brown Blood can be old blood. However, I'm not a doctor and even if I were, there's no way to tell over the Internet.
I'd suggest getting checked out to make sure everything is okay.