Understanding Unexpected Periods & Pregnancy Concerns

Question
My boyfriend and I have had sex for quite sometime now and we use to use protection. Lately he has been more ampt towards the "pull out" method. I told him that that is not a guaranteed method and the only guarantee is to not have sex at all. However; I recently had my menstrual cycle but it came 4 days earlier than usual and only lasted for one two actual days of bleeding then 2 days of nothing and 1 day of spotting. I am a firm believer that you can get pregnant on your cycle seeing as 3 of my closest friends are the product of that type of situation. Lately I have had an increase of appetite, constant nausea, need for lots of sleep, and back pains that are coming out of left field and I have mood swings that are very unlike me. I at first thought it could be an appendicitis but it doesn't fit with the classifications of those symptoms. I had recently been very stressed as well but I've been just as stressed before and that time caused me loss of appetite and no actual pains what so ever. So I guess what I'm trying to ask is "Is it possible that I'm pregnant or am I just having pains linked to a different medical issue possibly"?

Answer
It's always possible that you could be pregnant if you have had any sexual activity at all.  Getting a pregnancy test is an easy way to find out one way or the other, especially if it has been at least two weeks since you could have conceived.  If cost is an issue, check with your local Planned Parenthood office for free testing (they make you watch videos, but that's all).  You can also get very low cost pregnancy tests online from a variety of sources.