Could Missing My Period For Almost Three Months, Despite Negative Pregnancy Tests And Taking An I-Pill, Indicate A Problem?

i had my last periods on 27th november after that i had intercourse on 7th december then on 25th december nd then on 14th january till now i didnt had my periods its been almost 3months I also had home preganancy test nd it was negative I M VERY MUCH WORRIED ABOUT IT PLEASE HELP ME OUT. I had consumed an ipill(once) in september/october.