if its painful try drinking barley water as you need to alkalise your wee (its the acid that makes it painful). Drinking loads will dilute the bugs and flush it out but it might reoccur and turn into a kidney infection which is bloody painful. I would go to the doc and give a sample if you can. Poor you. They are horrible.
If it is just irritation of your bladder ,ie true cystitis, then just drinking lots of water could well sort it out.
If you have any infection there then you need antibiotics.
It's very difficult to work out if there is infection or just inflammation unless you are obviously very unwell with infection or you have waited 48hours to get a urine culture result back (by which time you may be unwell) so tbh I would always go for antibiotics.
is there an out-of-hours doctor's service you can go to? tbh it is worth catching before it gets nasty as then you would most likely have to take time off anyway I ended up with a kidney infection after getting cystisis once (didn't get ab's quickly enough as it was the weekend) and it was bloody painful I wouldn't chance it!
Lots of cranberry juice, you can also buy cranberyy capsules (for bladder health)... also if it is true cystitis, crink lots of water with bicarb of soda (to alkalize again). You should be able to feel if it's working (ie: if it gets more painful, go to GP and get AB's, not worth infection travelling up to kidney, can become VERY painful...)...