It depends on the pain. If it is not severe cramping with bleeding it should be normal. What kind of pain is it? Twinges and sharp pains are fairly common as your uterus begins to grow. Sometimes your bowels can cause discomfort as your body is adjusting to pregnancytoo.
Don't worry. That is completely normal due to stretching. You will probably have this throughout your pregnancy. I am 16wks, and still have it. It's on and off, though. Unless it gets REALLY painful (and I mean, REALLY), or unless you see some spotting (which is sometimes normal too, but they like you to call in to the dr and get an opinion if this happens), then you should be coming along just fine.
With all three of my kids, during the first 3 months i bled, cramped had pain, trickled fluid, passed clots, passed blood when i sneezed and coughed and still had very healthy babies, they couldn't find out why, but all the ultrasounds i had showed a healthy baby.
I'm having strething sharp pains on either side of my belly. Sort of where my ovaries are. I asked the nurse about it and she told me it's our body getting ready for a growing uterus. It's our stomach muscles stretching to support the lower portion of our uterus. All very normal.