Antibiotics and very long period cause for concern?

Patient: I have just finished a month of antibiotics for a dental issue. While i was on them i lapsed in taking my birth control consistently. In the last month i have recieved my period twice. The second time has lasted over 2 weeks. Is this normal after missing so many pills or should i be concerned? I have gotten back into my normal routine with my pill for a week yet my period shows no signs of stopping.