Period for 3 weeks on BC pill

So i’m on the birth control pill and have been for a year now and never had any issues missing days because i set alarms. but recently, i missed three days without realizing and by the time i realized, i knew my period would start bc i was cramping. i immediately got back on track with taking them, but my period started as a result of missing pills, and i’ve had it for almost 3 weeks now. is this normal for it to last this long after missing days?? or should i see my doctor?