Welcome to healthcare magic.Concerta
has no effect on pregnancy
.So yes you could become pregnant.But since you have your periods late,please do consult a gynecologist,to know what could be the reasons for your delayed periods.And you or your baby would not be in danger because of taking Concerta regularly as prescribed.If you have any problems such as loss of hunger,loss of sleep,then please do consult your treating doctor since these are usual side effects of Concerta.
Hope this answers your query.Will be available to answer your follow up queries.
Wish you good health.