I stopped taking the contraceptive pill a month ago because of the side effects, and I should normally have my period by now but I haven't, but I have lower abdominal pain. Is this normal? And how long will it take to regulate?

It is normal for your cycle to take some time to readjust after stopping hormonal contraception. It may take a few months for your menstruation to become regular again. If you have had unprotected sex recently and are concerned about pregnancy, you can take a pregnancy test in about ten days. Otherwise, try not to worry too much as your body should eventually return to its usual cycle.