Hello mam, thanks for trusting health care magic.
in irregular manner can result in failure of contraception
and thus result in pregnancy
ever since your pregcolor is negative it can be a very early pregnancy so not showing in urine so you can wait for a week and repeat the pregcolor test and in the meanwhile in case you get your periods then its okay. but after periods start taking your pills on regular time and daily.
In case you have further questions you can consult me on health care magic forum and i will be happy to help
Take care and wish you all the best.
Dr Manisha Jain.