It could be gas or it could just be the uterus expanding and putting pressure on your other organs.
I am the same way. I am 9 weeks and a day. I was having problems with cysts really bad before I got pregnant. I still have pains on my left side. I went to my Dr. and had an ultrasound and they said everything looked fine. My Dr. said that pains on your left side could be caused by gas. I know it doesn't feel like gas and it hurts like hell but that is what she said. She said it is very common. After a while they do seem to stop. Try to be careful of what you eat.