I got my period yesterday, and I noticed whilst I was changing my tampon that the menstruation smells sour and foul instead of that usual thick and cloying sweet smell. Bitter, almost like diarrhea.
It smells terrible, but the flow and colour seems to be completely normal, and it isn't so over-powering that the smell follows me about, its only noticeable when I change my tampon.
Any suggestions?

And on a side note, I'm in university and working a part-time job, as well as being in a new city, so seeing a doctor is something I don't know if I can do...unless walk-ins do that, and I've got trust issues. Anyways, does anyone have any idea?

The first thing I would suggest would be to stop using tampons and get some organic menstrual pads (or tampons, but I've gone off the whole tampon idea). Natracare is one brand I know of. If they don't have them in your usual grocery store then check a health food store. Alternatively, you can try a menstrual cup, such as the MoonCuo (UK) or DivaCup (US). Tampons contain all kinds of nasty things and even if you've never had a bad reaction before you could develop one now. Plus, if you have some sort of bacterial infection then you want to allow your vagina to breath and heal itself, so shoving cotton up there is not a good thing to continue.