Hello. I am very worried. This is kind of a personal topic but I need to discuss it with someone with knowledge of the kind. I am 15 years old (will be 16 in October) and I have had a boyfriend for 2 years. We have had unprotected sex a few times recently. I had a period at the end of last month but it was very light. I would put a tampon in and only the tip would be bloody. I have been on oral steroids for a sore throat and an ear ache but the doctor said I wouldn't gain much weight. The last time I went to the doctor I weighed 126 pounds and now I weigh 136. My stomach has been kind of round and I've gained a lot of weight. I have always been a pretty small girl. I am 5 foot and have been a medium size, but lately I have had people ask if I'm pregnant and I kind of look it. I have also been cramping a bit. Am I just worried? I need some reassurance.

Since there is a chance for pregnancy, (some people have light bleeding in early pregnancy), it would be wise to use a pregnancy test (follow the directions carefully).

Is there a reason you have been having unprotected sex? Are you emotionally and financially able to raise a child at this point in your life?

Be smart and either stop having sex (the best solution), or at the very least use proper protection yourself AND insist that your boyfriend wears a condom. YOU have to protect yourself. If your boyfriend refuses, then you'll know that he cares more about himself than he does about you.

At one month pregnant, you do not gain 10 pounds. With that said, of course if you have been having sex, any sex, there is a chance. If you are not using protection, even a higher chance.

So try a pregnancy test, use it first thing in the morning, as soon as you wake up.
If negative, see if you get this months period, and if NO, wait two week and test again

Prednisone?
You need to find the cause of the earache and sore throat! It could be dental. See a dentist. It could be a bacterial infection of a sinus near your ear, or a eustachian tube, and that would mean antibiotics, much as I hate people taking so many of those. Demand that the doctor find out.
As for unprotected sex, good grief! You seem quite willing to play Russian roulette, hoping you aren't pregnant but doing nothing to prevent it. Get to work on some real birth control, or abstain.