Hmm, this does look more like your stomach than your bowels unless you actually are farther a long in a pregnancy, in which case if might be that you would be "showing a little more". Is it something that just happened or something you just noticed or has it been getting worse (bigger over time) and is there any pain associated with it? Just think of where exactly it hurts when you have period cramping and then you will be able to better tell if what you have would be from a pregnancy.
The baby starts to grow from your pelvic bone upwards, so usually there would be somewhat of what you would see in your picture, but more below your bellybutton, but everyone's different and carries a baby differently too. The bowel distension doesn't really look like that.
If what I see in the picture is part of pregnancy, I'm thinking that you would be much father along than a months, so you could actually take a test now based on that. I'm sorry I can't tell you more in that respect.
If it isn't pregnancy, then maybe you should see a doctor. Unless you have quite a bit of bloating from PMS, that doesn't look like something that's comfortable if your abs are as nice looking as I think they are without the bloating.
BTW, I was wondering if you were from England, just curious, doesn't have anything to do with this lol. I used to have this friend in England and I haven't heard from him in forever, but his name was Grant, and we all called him Vamp since he loved Vampires and his girlfriend's name was Leigh lol. Could be just wierd coincidence.
I hope this helps you out somewhat. Keep us updated and let me know if I can help you out anymore with this....I'm doing the best I can.