My period won’t stop

I have had a very weird year with my period. It started a year ago, I didn’t have my period in December and then started back in January. I then didn’t have a period until April, then July, then I started again in September and bled almost a month, stopped for about 3 weeks, then bled a few weeks, off almost 2 weeks and now have been bleeding for 3 weeks and it’s very very heavy.

I went to the doctor on Thursday and they took blood, and scheduled for me to have an internal sonogram. Depending on how thick my uterus lining is will determine if they will do a biopsy.

Has anyone experienced this and it not turn out to be serious? I’m 33 and always had a regular period until this started.