Could Heavy Bleeding Be Due To Uterine Fibroids Or Contraceptive Pills?

Hi, I am 36 years old and am on a low dose contraceptive pill. I have a unterine fibroid which caused heavy bleeding in the past, thus the contracteptive pill. Recently I began bleeding between menstral cycles and have not stopped bleeding for the past 5 weeks. I am having a hard time getting in touch with my doctor (because I live in Canada and the doctors are very hard to reach!) Should I be worried? Has the fibroid grown which is causing the bleeding, or should I be worried about something else? Thanks.