Tiedinknots, I don't know how long the bottle lasted you, but it's a pretty good rule of thumb that you need to give probiotics a month to take full effect. If you took them for a month and saw no change, then you're not likely to get any change. Continuing to take them won't hurt you, but most people would prefer to give up the cost. Although, if you can tolerate dairy, acidophillus milk and/or yogurt are both good ways to get some probiotics into your diet every day without spending a lot of money. The pill form is definitely something you should consider taking, though, when you have to be on antibiotics. Antibiotics tear me up (worse than usual) if I don't take probiotics.
Stilltiredofit51, a bacteria overgrowth test is really easy; they make you breathe into a machine, like a breathalyzer test. If you are breathing out gases that you shouldn't be, or in quantities that aren't normal, then they know there's something in there that shouldn't be, because bad bacteria farts gases which are not normally produced by the guts.