you take your pills regularly ? and in same time every day ...so why you think you are pregnant?
may be due increase salts in urine , may be due to urinary infections , may be due to vaginal infections spread to urinary tract
, or even due to cold
so if you have itching , foul smell of urine , please make urine analysis
pills have low failure rate , so it is less likely to be pregnant if you take them regularly , wait for your date of menses , and do pregnancy