how do you tell the difference between chlamidia and cystitis?

well for the past 2 weeks i have been needing to pee urgently and quite often also my urine smells weird and i have been getting abdominal pains, and it sumtimes hurts when i pee and shortly after i urinate i need to go again but its only a little bit, but my urine isn't a odd colour you see about 8 months ago i sleep with this boy and iwe didnt use protection stupid i know but it happened and i was a bit worried coz i have been with my boyfriend for 3 years and this happened after we had, had an arguement and i felt really bad about it straight away and i dont want him to find out coz he's my world so im kinda hoping its not chlamidia please help me x

The only thing you can do is see your doctor. Chlamydia tends to not have any symptoms at all so it's likely to just be a water infection, however the best thing for you to do is visit your doctor who will do a quick swap or urine test and you can find out for certain. It's not something that can just be ignored as it can leave you infertile and PLEASE use condoms in future.
If you do have chlamydia you will need to tell your boyfriend as if you have passed it on he will re-infect you.